A vital part of PIPAC’s package of services is basic and applied research conducted independently or in cooperation with client companies.
Institute Personnel and their Research Interests
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Armando Victor M. Guidote, Jr., Ph.D.
Research Interests:
Organic Chemistry, Natural Products, Chemistry Education
Click here to see the list of his publications.
Armando Jerome H. de Jesus, Jr., Ph.D.
Research Interests:
Molecular dynamics simulations, Membrane-protein interactions, Membrane protein-small molecule interactions
Click here to see the list of his publications.
Ronaldo M. Fabicon, Ph.D.
Research Interests:
Industrial Chemistry
Click here to see the list of his publications.
Crisanto M. Lopez, Dr.rer.nat
Research Interests:
Infection Biology, Fungal Biotechnology
Click here to see the list of his publications.
Giselle Grace F. Lim-Co Yu Kang, Ph.D
Research Interests:
Biochemistry, Enzymes, Analytical Chemistry
Click here to see the list of her publications.
Gilbert U. Yu, D.Eng
Research Interests:
Materials Science (Polymers and Supramolecules), Chemical Education, Development of Lab Experiment Modules
Click here to see the list of his publications.
Ian Ken D. Dimzon, Ph.D
Research Interests:
Applied Analytical Chemistry, Mass Spectrometry, Chemical Metrology
Click here to see the list of his publications.
Anna Carissa M. San Esteban, Ph.D
Research Interests:
Electrochemistry (corrosion, electrocatalytic processes); Coordination Chemistry (coordination polymers, metal-organic frameworks)
Click here to see the list of her publications.
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Selected Publications
2023
Michael Russelle Alvarez; Florence De Juan; Qingwen Zhou; Ian Ken D. Dimzon; Sheryl Joyce Grijaldo; Sean Sunga; Francisco Heralde; Carlito B. Lebrilla; Gladys Cherisse Completo; Ruel C. Nacario
Comparative proteomics reveals anticancer compounds from Lansium domesticum against NSCLC cells target mitochondrial processes Journal Article
In: Cell Biochemistry & Function, vol. 41, no. 2, pp. 166–176, 2023, ISSN: 1099-0844.
@article{Alvarez2023,
title = {Comparative proteomics reveals anticancer compounds from \textit{Lansium domesticum} against NSCLC cells target mitochondrial processes},
author = {Michael Russelle Alvarez and Florence De Juan and Qingwen Zhou and Ian Ken D. Dimzon and Sheryl Joyce Grijaldo and Sean Sunga and Francisco Heralde and Carlito B. Lebrilla and Gladys Cherisse Completo and Ruel C. Nacario},
doi = {10.1002/cbf.3768},
issn = {1099-0844},
year = {2023},
date = {2023-03-00},
journal = {Cell Biochemistry & Function},
volume = {41},
number = {2},
pages = {166--176},
publisher = {Wiley},
abstract = {Abstract Lansium domesticum is identified as a potential source of anticancer compounds. However, there are minimal studies on its anti‐lung cancer properties as well as its mechanism of action. Here, we show the specificity of lanzones hexane (LH) leaf extracts to non‐small cell lung cancer cells (A549) compared to normal lung fibroblast cells (CCD19‐Lu) and normal epithelial prostate cells (PNT2). Subsequent bioassay‐guided fractionation of the hexane leaf extracts identified two bioactive fractions with IC50 values of 2.694 μg/ml (LH6‐6) and 2.883 μg/ml (LH7‐6). LH 6‐6 treatment (1 μg/ml concentration) also showed a significantly reduced migration potential of A549 relative to the control. Thirty‐one phytocompounds were isolated and identified using gas chromatography–mass spectrometric (MS) analysis and were then subjected to network pharmacology analysis to assess its effects on lung cancer target proteins. Using liquid chromatography‐tandem mass spectrometry proteomics experiments, we were able to show that these compounds cause cytotoxic effects through targeting mitochondrial processes in A549 lung cancer cells.
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2018
Ian Ken D. Dimzon; Ann Selma Morata; Janine Müller; Roy Kristian C. Yanela; Stephan Lebertz; Heike Weil; Teresita R. Perez; Fabian M. Dayrit; Thomas P. Knepper
Trace organic chemical pollutants from the lake waters of San Pablo City, Philippines by targeted and non-targeted analysis Journal Article
In: Science of The Total Environment, vol. 639, pp. 588-595, 2018.
Abstract | Links | Tags: aquaculture, artificial sweeteners, pesticides, Philippines, small lakes, surfactants
@article{Dimzon2018,
title = {Trace organic chemical pollutants from the lake waters of San Pablo City, Philippines by targeted and non-targeted analysis},
author = {Ian Ken D. Dimzon and Ann Selma Morata and Janine Müller and Roy Kristian C. Yanela and Stephan Lebertz and Heike Weil and Teresita R. Perez and Fabian M. Dayrit and Thomas P. Knepper},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0048969718318680},
doi = {10.1016/j.scitotenv.2018.05.217},
year = {2018},
date = {2018-05-26},
journal = {Science of The Total Environment},
volume = {639},
pages = {588-595},
abstract = {More than half of the freshwater lakes in the Philippines are small with surface areas of <2 km2. The dynamics in these lakes are different from those in the bigger lakes. This study was conducted to determine the organic pollutants and their sources in three of the seven lakes of San Pablo City in Laguna, Philippines: lakes Palakpakin, Sampaloc, and Pandin. Gas Chromatography-Mass Spectrometry (GC–MS) and Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS) were used in the targeted and non-targeted analysis of the lake water samples. The three lakes are all volcanic crater lakes but are exposed to different anthropogenic activities, which includes domestic activities, livelihood (farming and aquaculture) and eco-tourism.
Due to the presence of rice fields and fruit plantations, chlorpyrifos was detected in the three lakes while other pesticides like cypermethrin, picolinafen and quinoxyfen were additionally found in Lake Sampaloc, which is the biggest of the three lakes and located within the urbanized section of the city. Traces of different surfactants (linear alkylbenzene sulfonates, secondary alkyl sulfonates, alkyl sulfates, alkyl ether sulfates), biocide benzalkonium chloride, insect repellent diethyltoluamide, antibiotics (sulfadiazine and sulfamethoxazole), hypertension drug telmisartan, phosphate-based fire retardants, and artificial sweeteners (acesulfame, cyclamate, saccharin and sucralose) were detected in lakes Sampaloc and Palakpakin. The same surfactants, artificial sweeteners, insect repellant and phosphate-based fire retardants were also found in Lake Pandin, which is mainly used for eco-tourism activities like swimming and boating.
The results of this study suggest that the organic pollutants present in the small lakes can be linked to the various human activities in the immediate lake environment. Because small lakes are more prone to environmental stresses, human activities in the said lakes must be regulated to ensure sustainable development.},
keywords = {aquaculture, artificial sweeteners, pesticides, Philippines, small lakes, surfactants},
pubstate = {published},
tppubtype = {article}
}
More than half of the freshwater lakes in the Philippines are small with surface areas of <2 km2. The dynamics in these lakes are different from those in the bigger lakes. This study was conducted to determine the organic pollutants and their sources in three of the seven lakes of San Pablo City in Laguna, Philippines: lakes Palakpakin, Sampaloc, and Pandin. Gas Chromatography-Mass Spectrometry (GC–MS) and Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS) were used in the targeted and non-targeted analysis of the lake water samples. The three lakes are all volcanic crater lakes but are exposed to different anthropogenic activities, which includes domestic activities, livelihood (farming and aquaculture) and eco-tourism.
Due to the presence of rice fields and fruit plantations, chlorpyrifos was detected in the three lakes while other pesticides like cypermethrin, picolinafen and quinoxyfen were additionally found in Lake Sampaloc, which is the biggest of the three lakes and located within the urbanized section of the city. Traces of different surfactants (linear alkylbenzene sulfonates, secondary alkyl sulfonates, alkyl sulfates, alkyl ether sulfates), biocide benzalkonium chloride, insect repellent diethyltoluamide, antibiotics (sulfadiazine and sulfamethoxazole), hypertension drug telmisartan, phosphate-based fire retardants, and artificial sweeteners (acesulfame, cyclamate, saccharin and sucralose) were detected in lakes Sampaloc and Palakpakin. The same surfactants, artificial sweeteners, insect repellant and phosphate-based fire retardants were also found in Lake Pandin, which is mainly used for eco-tourism activities like swimming and boating.
The results of this study suggest that the organic pollutants present in the small lakes can be linked to the various human activities in the immediate lake environment. Because small lakes are more prone to environmental stresses, human activities in the said lakes must be regulated to ensure sustainable development.
Due to the presence of rice fields and fruit plantations, chlorpyrifos was detected in the three lakes while other pesticides like cypermethrin, picolinafen and quinoxyfen were additionally found in Lake Sampaloc, which is the biggest of the three lakes and located within the urbanized section of the city. Traces of different surfactants (linear alkylbenzene sulfonates, secondary alkyl sulfonates, alkyl sulfates, alkyl ether sulfates), biocide benzalkonium chloride, insect repellent diethyltoluamide, antibiotics (sulfadiazine and sulfamethoxazole), hypertension drug telmisartan, phosphate-based fire retardants, and artificial sweeteners (acesulfame, cyclamate, saccharin and sucralose) were detected in lakes Sampaloc and Palakpakin. The same surfactants, artificial sweeteners, insect repellant and phosphate-based fire retardants were also found in Lake Pandin, which is mainly used for eco-tourism activities like swimming and boating.
The results of this study suggest that the organic pollutants present in the small lakes can be linked to the various human activities in the immediate lake environment. Because small lakes are more prone to environmental stresses, human activities in the said lakes must be regulated to ensure sustainable development.
2017
Sascha Klein; Ian Ken D. Dimzon; Jan Eubeler; Thomas P. Knepper
In: Freshwater Microplastics, vol. 58, pp. 51-67, Springer, Cham, 2017, ISBN: 978-3-319-61615-5.
@inbook{Klein2017,
title = {Analysis, Occurrence, and Degradation of Microplastics in the Aqueous Environment microplastics in the aqueous environment},
author = {Sascha Klein and Ian Ken D. Dimzon and Jan Eubeler and Thomas P. Knepper},
url = {https://link.springer.com/chapter/10.1007/978-3-319-61615-5_3},
doi = { 10.1007/978-3-319-61615-5_3},
isbn = {978-3-319-61615-5},
year = {2017},
date = {2017-07-20},
booktitle = {Freshwater Microplastics},
volume = {58},
pages = {51-67},
publisher = {Springer, Cham},
series = {The Handbook of Environmental Chemistry},
abstract = {Synthetic polymers are one of the most significant pollutants in the aquatic environment. Most research focused on small plastic particles, so-called microplastics (particle size, 1–5,000 μm). Compared to macroplastics, the small size complicates their determination in environmental samples and demands for more sophisticated analytical approaches. The detection methods of microplastics reported in the past are highly diverse. This chapter summarizes different strategies for the sampling of water and sediment and sample treatments, including the separation of plastic particles and removal of natural debris that are necessary prior the identification of microplastics. Moreover, the techniques used for the identification of plastics particles are presented in this chapter.
With the application of the method described in this chapter, microplastics were detected in freshwater systems, such as rivers and lakes worldwide. The abundance of microplastics reported in the studies varied in more than three orders of magnitude.
Furthermore, microplastics are not uniform, as there are many different types of synthetic polymers commercially available. Consequently, a variety of different polymer types is present in the aquatic environment. The knowledge on the type of polymer provides additional information for scientists: the type of polymer dictates its physicochemical properties and the degradation. The environmental degradation of plastics is an important factor for the formation, distribution, and accumulation of microplastics in the aquatic system. Thus, this chapter also summarizes the degradation pathways for synthetic polymers in the environment.},
keywords = {-},
pubstate = {published},
tppubtype = {inbook}
}
Synthetic polymers are one of the most significant pollutants in the aquatic environment. Most research focused on small plastic particles, so-called microplastics (particle size, 1–5,000 μm). Compared to macroplastics, the small size complicates their determination in environmental samples and demands for more sophisticated analytical approaches. The detection methods of microplastics reported in the past are highly diverse. This chapter summarizes different strategies for the sampling of water and sediment and sample treatments, including the separation of plastic particles and removal of natural debris that are necessary prior the identification of microplastics. Moreover, the techniques used for the identification of plastics particles are presented in this chapter.
With the application of the method described in this chapter, microplastics were detected in freshwater systems, such as rivers and lakes worldwide. The abundance of microplastics reported in the studies varied in more than three orders of magnitude.
Furthermore, microplastics are not uniform, as there are many different types of synthetic polymers commercially available. Consequently, a variety of different polymer types is present in the aquatic environment. The knowledge on the type of polymer provides additional information for scientists: the type of polymer dictates its physicochemical properties and the degradation. The environmental degradation of plastics is an important factor for the formation, distribution, and accumulation of microplastics in the aquatic system. Thus, this chapter also summarizes the degradation pathways for synthetic polymers in the environment.
With the application of the method described in this chapter, microplastics were detected in freshwater systems, such as rivers and lakes worldwide. The abundance of microplastics reported in the studies varied in more than three orders of magnitude.
Furthermore, microplastics are not uniform, as there are many different types of synthetic polymers commercially available. Consequently, a variety of different polymer types is present in the aquatic environment. The knowledge on the type of polymer provides additional information for scientists: the type of polymer dictates its physicochemical properties and the degradation. The environmental degradation of plastics is an important factor for the formation, distribution, and accumulation of microplastics in the aquatic system. Thus, this chapter also summarizes the degradation pathways for synthetic polymers in the environment.
2016
Ian Ken D. Dimzon; Joke Westerveld; Christoph Gremmel; Tobias Frömel; Thomas P. Knepper; Pim de Voogt
Sampling and simultaneous determination of volatile per- and polyfluoroalkyl substances in wastewater treatment plant air and water Journal Article
In: Analytical and Bioanalytical Chemistry, vol. 409, pp. 1935-1404, 2016.
Abstract | Links | Tags: volatile PFAS and GC-MS and WWTP and influents and effluents and air
@article{Dimzon2016,
title = {Sampling and simultaneous determination of volatile per- and polyfluoroalkyl substances in wastewater treatment plant air and water},
author = {Ian Ken D. Dimzon and Joke Westerveld and Christoph Gremmel and Tobias Frömel and Thomas P. Knepper and Pim de Voogt},
url = {https://link.springer.com/article/10.1007/s00216-016-0072-1},
doi = {10.1007/s00216-016-0072-1},
year = {2016},
date = {2016-11-25},
journal = {Analytical and Bioanalytical Chemistry},
volume = {409},
pages = {1935-1404},
abstract = {Volatile per- and polyfluoroalkyl substances (PFASs) are often used as precursors in the synthesis of nonvolatile PFASs. The volatile PFASs, which include the perfluoroalkyl iodides (PFAIs), fluorotelomer iodides (FTIs), fluorotelomer alcohols (FTOHs), fluorotelomer olefins (FTOs), fluorotelomer acrylates (FTACs), and fluorotelomer methacrylates (FTMACs), are often produced starting from the telomerization process. These volatile compounds can be present in the air and water environment and can be transformed into highly persistent perfluoroalkyl carboxylic acids. With the exception of FTOHs, which are well studied, the determination of other volatile PFASs is also of prime importance in studying the sources and fate of PFASs. In this study, a method was developed to determine representative precursor compounds that included PFAIs, FTIs, FTOs, FTACs, and FTMACs in wastewater treatment plant (WWTP) air and water samples. The sampling and sample preparation step involved the use of solid-phase extraction (SPE) cartridges with HLB™ material to enrich the analyte. Gas chromatography with mass spectrometry was employed for the detection and quantification of the analytes. Method validation results showed high linearity and sensitivity in the positive electron ionization-selected ion monitoring mode (+EI-SIM). The absolute instrumental limits of detection were in the range of 0.5 to 2 pg. The method detection limit (MDL) in air was 1 ng/m3 with the exception of the FTACs which could be only be detected at concentrations higher than 40 ng/m3. The MDL in water was 10 ng/L. Direct spiking of the cartridges and analyte introduction by volatilization from the glass surface onto the SPE material had recoveries between 86 and 100%. The volatile PFASs were shown to readily partition into the air rather than into water. Consequently, large losses in the amount of PFASs were observed when these were spiked into the water.},
keywords = {volatile PFAS and GC-MS and WWTP and influents and effluents and air},
pubstate = {published},
tppubtype = {article}
}
Volatile per- and polyfluoroalkyl substances (PFASs) are often used as precursors in the synthesis of nonvolatile PFASs. The volatile PFASs, which include the perfluoroalkyl iodides (PFAIs), fluorotelomer iodides (FTIs), fluorotelomer alcohols (FTOHs), fluorotelomer olefins (FTOs), fluorotelomer acrylates (FTACs), and fluorotelomer methacrylates (FTMACs), are often produced starting from the telomerization process. These volatile compounds can be present in the air and water environment and can be transformed into highly persistent perfluoroalkyl carboxylic acids. With the exception of FTOHs, which are well studied, the determination of other volatile PFASs is also of prime importance in studying the sources and fate of PFASs. In this study, a method was developed to determine representative precursor compounds that included PFAIs, FTIs, FTOs, FTACs, and FTMACs in wastewater treatment plant (WWTP) air and water samples. The sampling and sample preparation step involved the use of solid-phase extraction (SPE) cartridges with HLB™ material to enrich the analyte. Gas chromatography with mass spectrometry was employed for the detection and quantification of the analytes. Method validation results showed high linearity and sensitivity in the positive electron ionization-selected ion monitoring mode (+EI-SIM). The absolute instrumental limits of detection were in the range of 0.5 to 2 pg. The method detection limit (MDL) in air was 1 ng/m3 with the exception of the FTACs which could be only be detected at concentrations higher than 40 ng/m3. The MDL in water was 10 ng/L. Direct spiking of the cartridges and analyte introduction by volatilization from the glass surface onto the SPE material had recoveries between 86 and 100%. The volatile PFASs were shown to readily partition into the air rather than into water. Consequently, large losses in the amount of PFASs were observed when these were spiked into the water.
Tobias Frömel; Christoph Gremmel; Ian Ken D. Dimzon; Heike Weil; Thomas P. Knepper; Pim de Voogt
Umweltbundesamt, 2016, ISBN: 1862-4804.
@book{Frömel2016,
title = {Investigations on the presence and behavior of precursors to perfluoroalkyl substances in the environment as a preparation of regulatory measures},
author = {Tobias Frömel and Christoph Gremmel and Ian Ken D. Dimzon and Heike Weil and Thomas P. Knepper and Pim de Voogt},
url = {https://www.umweltbundesamt.de/publikationen/investigations-on-the-presence-behavior-of},
isbn = {1862-4804},
year = {2016},
date = {2016-08-01},
publisher = {Umweltbundesamt},
abstract = {Wastewater treatment plants (WWTPs) have been identified as a significant pathway for the introduction of perfluoroalkyl and polyfluoroalkyl substances (PFASs) to natural waters. It was observed in several studies that the concentration of certain PFASs were higher in the WWTP effluent compared to the corresponding influent. The objective of the present study was the identification of potential precursor substances of persistent perfluoroalkyl acids (PFAAs) in WWTPs and indoor rooms in order to support the preparation of regulatory measures.},
keywords = {-},
pubstate = {published},
tppubtype = {book}
}
Wastewater treatment plants (WWTPs) have been identified as a significant pathway for the introduction of perfluoroalkyl and polyfluoroalkyl substances (PFASs) to natural waters. It was observed in several studies that the concentration of certain PFASs were higher in the WWTP effluent compared to the corresponding influent. The objective of the present study was the identification of potential precursor substances of persistent perfluoroalkyl acids (PFAAs) in WWTPs and indoor rooms in order to support the preparation of regulatory measures.
Ian Ken D. Dimzon; Tobias Frömel; Thomas P. Knepper
Characterization of 3-Aminopropyl Oligosilsesquioxane Journal Article
In: Analytical Chemistry, vol. 88, no. 9, pp. 4894-4902, 2016.
Abstract | Links | Tags: condensation, ionization, ions, mass spectrometry, silsesquioxanes
@article{Dimzon2016b,
title = {Characterization of 3-Aminopropyl Oligosilsesquioxane},
author = {Ian Ken D. Dimzon and Tobias Frömel and Thomas P. Knepper},
url = {https://pubs.acs.org/doi/abs/10.1021/acs.analchem.6b00732},
doi = {10.1021/acs.analchem.6b00732},
year = {2016},
date = {2016-05-03},
journal = {Analytical Chemistry},
volume = {88},
number = {9},
pages = {4894-4902},
abstract = {The synthesis routes in the production of polysilsesquioxanes have largely relied upon in situ formations. This perspective often leads to polymers in which their basic structures including molecular weight and functionality are unknown [Lichtenhan, J. D.; et al. Silsesquioxane-siloxane copolymers from polyhedral silsesquioxanes Macromolecules, 1993, 26, 2141−2142, http://dx.doi.org/10.1021/ma0060a053]. For a better understanding of the polysilsesquioxane properties and applications, there is a need to develop more techniques to enable their chemical characterization. An innovative method was developed to determine the molecular weight distribution (MWD) of an oligosilsesquioxane synthesized in-house from (3-aminopropyl)triethoxysilane. This method, which can be applied to other silsesquioxanes, siloxanes, and similar oligomers and polymers, involved separation using high performance liquid chromatography (HPLC) and detection using mass spectrometry (MS) with electrospray ionization (ESI). The novelty of the method lies on the unique determination of the absolute concentrations of the individual homologues present in the sample formulation. The use of absolute concentrations is necessary in estimating the MWD of the formulation when relative percentage, which is based solely on mass spectral ion intensities, becomes irrelevant due to the disproportionate response factors of the homologues. Determination of absolute concentration requires the use of single-homologue calibration standards. Because of commercial unavailability, these standards were prepared by efficient fractionation of the original formulation.},
keywords = {condensation, ionization, ions, mass spectrometry, silsesquioxanes},
pubstate = {published},
tppubtype = {article}
}
The synthesis routes in the production of polysilsesquioxanes have largely relied upon in situ formations. This perspective often leads to polymers in which their basic structures including molecular weight and functionality are unknown [Lichtenhan, J. D.; et al. Silsesquioxane-siloxane copolymers from polyhedral silsesquioxanes Macromolecules, 1993, 26, 2141−2142, http://dx.doi.org/10.1021/ma0060a053]. For a better understanding of the polysilsesquioxane properties and applications, there is a need to develop more techniques to enable their chemical characterization. An innovative method was developed to determine the molecular weight distribution (MWD) of an oligosilsesquioxane synthesized in-house from (3-aminopropyl)triethoxysilane. This method, which can be applied to other silsesquioxanes, siloxanes, and similar oligomers and polymers, involved separation using high performance liquid chromatography (HPLC) and detection using mass spectrometry (MS) with electrospray ionization (ESI). The novelty of the method lies on the unique determination of the absolute concentrations of the individual homologues present in the sample formulation. The use of absolute concentrations is necessary in estimating the MWD of the formulation when relative percentage, which is based solely on mass spectral ion intensities, becomes irrelevant due to the disproportionate response factors of the homologues. Determination of absolute concentration requires the use of single-homologue calibration standards. Because of commercial unavailability, these standards were prepared by efficient fractionation of the original formulation.
2015
Ian Ken D. Dimzon; Xenia Trier; Tobias Frömel; Rick Helmus; Thomas P. Knepper; Pim de Voogt
High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation Journal Article
In: Journal of The American Society for Mass Spectrometry, vol. 27, no. 2, pp. 309-318, 2015.
Abstract | Links | Tags: higher-order mass defect, HRMS, PFPE
@article{Dimzon2015,
title = {High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation},
author = {Ian Ken D. Dimzon and Xenia Trier and Tobias Frömel and Rick Helmus and Thomas P. Knepper and Pim de Voogt},
url = {https://pubs.acs.org/doi/abs/10.1021/jasms.8b05203},
doi = {10.1021/jasms.8b05203},
year = {2015},
date = {2015-10-30},
journal = {Journal of The American Society for Mass Spectrometry},
volume = {27},
number = {2},
pages = {309-318},
abstract = {High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid of an instrument data processor. Highly accurate mass spectral data enabled the calculation of higher-order mass defects. The different plots of MW and the nth-order mass defects (up to n = 3) could aid in assessing the structure of the different repeating units and estimating their absolute and relative number per molecule. The three major repeating units were -C2H4O-, -C2F4O-, and -CF2O-. Tandem MS was used to identify the end groups that appeared to be phosphates, as well as the possible distribution of the repeating units. Reversed-phase HPLC separated of the polymer molecules on the basis of number of nonpolar repeating units. The elucidated structure resembles the structure in the published manufacturer technical data. This analytical approach to the characterization of a PFPE-based formulation can serve as a guide in analyzing not just other PFPE-based formulations but also other fluorinated and non-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health.},
keywords = {higher-order mass defect, HRMS, PFPE},
pubstate = {published},
tppubtype = {article}
}
High resolution mass spectrometry (HRMS) was successfully applied to elucidate the structure of a polyfluorinated polyether (PFPE)-based formulation. The mass spectrum generated from direct injection into the MS was examined by identifying the different repeating units manually and with the aid of an instrument data processor. Highly accurate mass spectral data enabled the calculation of higher-order mass defects. The different plots of MW and the nth-order mass defects (up to n = 3) could aid in assessing the structure of the different repeating units and estimating their absolute and relative number per molecule. The three major repeating units were -C2H4O-, -C2F4O-, and -CF2O-. Tandem MS was used to identify the end groups that appeared to be phosphates, as well as the possible distribution of the repeating units. Reversed-phase HPLC separated of the polymer molecules on the basis of number of nonpolar repeating units. The elucidated structure resembles the structure in the published manufacturer technical data. This analytical approach to the characterization of a PFPE-based formulation can serve as a guide in analyzing not just other PFPE-based formulations but also other fluorinated and non-fluorinated polymers. The information from MS is essential in studying the physico-chemical properties of PFPEs and can help in assessing the risks they pose to the environment and to human health.
Ian Ken D. Dimzon
Analytical and Statistical Approaches in the Characterization of Synthetic Polymers Book
Proefschrift Universiteit van Amsterdam, 2015, ISBN: 9789491407178.
@book{Dimzon2015b,
title = {Analytical and Statistical Approaches in the Characterization of Synthetic Polymers},
author = {Ian Ken D. Dimzon},
url = {https://dare.uva.nl/search?identifier=e5fe675e-b25c-48af-bc9a-3bc9e99c8763},
isbn = {9789491407178},
year = {2015},
date = {2015-05-22},
pages = {157},
publisher = {Proefschrift Universiteit van Amsterdam},
abstract = {Polymers vary in terms of the monomer/s used; the number, distribution and type of linkage of monomers per molecule; and the side chains and end groups attached. Given this diversity, traditional single-technique approaches to characterization often give limited and inadequate information about a given polymer. Multi-technique but polymer-specific approach was found to be an appropriate alternative. This strategy was applied in characterizing polymers of a wide range of properties from simple polyethylene gylcol, to polycationic chitosan and aminopropyl based oligosiloxanes, and to polydiverse polyfluorinated polyethoxylates.
Mass Spectrometry (MS) was used to characterize the different polymers. Different modes of sample introduction, ionization, mass analysis and detection were surveyed. The nature of the monomer units, the size and the polydispersity of polymers are the important factors that affect the detection and quantification of the polymer moieties using MS. MS gave information not just on the molecular weight but also about the repeating units of the polymers.
Traditional techniques like size exclusion chromatography and infrared spectroscopy were also used to obtain complementary information on the properties of polymers. Chemometric techniques like partial least squares aided in the statistical evaluation of experimental data.
The research works included in this thesis have demonstrated that polymer characterization can be accomplished with the use of a combination of different instrumental and statistical techniques. This strategy allows the researcher to explore additional information about the polymer formulation and correlate these to some observed behaviors or activities.},
keywords = {-},
pubstate = {published},
tppubtype = {book}
}
Polymers vary in terms of the monomer/s used; the number, distribution and type of linkage of monomers per molecule; and the side chains and end groups attached. Given this diversity, traditional single-technique approaches to characterization often give limited and inadequate information about a given polymer. Multi-technique but polymer-specific approach was found to be an appropriate alternative. This strategy was applied in characterizing polymers of a wide range of properties from simple polyethylene gylcol, to polycationic chitosan and aminopropyl based oligosiloxanes, and to polydiverse polyfluorinated polyethoxylates.
Mass Spectrometry (MS) was used to characterize the different polymers. Different modes of sample introduction, ionization, mass analysis and detection were surveyed. The nature of the monomer units, the size and the polydispersity of polymers are the important factors that affect the detection and quantification of the polymer moieties using MS. MS gave information not just on the molecular weight but also about the repeating units of the polymers.
Traditional techniques like size exclusion chromatography and infrared spectroscopy were also used to obtain complementary information on the properties of polymers. Chemometric techniques like partial least squares aided in the statistical evaluation of experimental data.
The research works included in this thesis have demonstrated that polymer characterization can be accomplished with the use of a combination of different instrumental and statistical techniques. This strategy allows the researcher to explore additional information about the polymer formulation and correlate these to some observed behaviors or activities.
Mass Spectrometry (MS) was used to characterize the different polymers. Different modes of sample introduction, ionization, mass analysis and detection were surveyed. The nature of the monomer units, the size and the polydispersity of polymers are the important factors that affect the detection and quantification of the polymer moieties using MS. MS gave information not just on the molecular weight but also about the repeating units of the polymers.
Traditional techniques like size exclusion chromatography and infrared spectroscopy were also used to obtain complementary information on the properties of polymers. Chemometric techniques like partial least squares aided in the statistical evaluation of experimental data.
The research works included in this thesis have demonstrated that polymer characterization can be accomplished with the use of a combination of different instrumental and statistical techniques. This strategy allows the researcher to explore additional information about the polymer formulation and correlate these to some observed behaviors or activities.
2014
Ian Ken D. Dimzon; Thomas P. Knepper
Degree of deacetylation of chitosan by infrared spectroscopy and partial least squares Journal Article
In: International Journal of Biological Macromolecules, vol. 72, pp. 939-945, 2014.
Abstract | Links | Tags: chitosan, degree of deacetylation, partial least square
@article{Dimzon2014,
title = {Degree of deacetylation of chitosan by infrared spectroscopy and partial least squares},
author = {Ian Ken D. Dimzon and Thomas P. Knepper},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0141813014006631},
doi = {10.1016/j.ijbiomac.2014.09.050},
year = {2014},
date = {2014-10-12},
journal = {International Journal of Biological Macromolecules},
volume = {72},
pages = {939-945},
abstract = {The determination of the degree of deacetylation of highly deacetylated chitosan by infrared (IR) spectroscopy was significantly improved with the use of partial least squares (PLS). The IR spectral region from 1500 to 1800 cm−1 was taken as the dataset. Different PLS models resulting from various data pre-treatments were evaluated and compared. The PLS model that gave excellent internal and external validation performance came from the data that were corrected for the baseline and that was normalized relative to the maximum corrected absorbance. Analysis of the PLS loadings plot showed that the important variables in the spectral region came from the absorption maxima related to the amide bands at 1660 and 1550 cm−1 and amine band at 1600 cm−1. IR-PLS results were comparable to the results obtained by potentiometric titration. IR-PLS results were found to be more precise and rugged compared to the usual IR absorbance ratio method. This is consistent with the fact that IR spectral resolution is not really high and that the absorption at a single wavelength is influenced by other factors like hydrogen bonding and the presence of water.},
keywords = {chitosan, degree of deacetylation, partial least square},
pubstate = {published},
tppubtype = {article}
}
The determination of the degree of deacetylation of highly deacetylated chitosan by infrared (IR) spectroscopy was significantly improved with the use of partial least squares (PLS). The IR spectral region from 1500 to 1800 cm−1 was taken as the dataset. Different PLS models resulting from various data pre-treatments were evaluated and compared. The PLS model that gave excellent internal and external validation performance came from the data that were corrected for the baseline and that was normalized relative to the maximum corrected absorbance. Analysis of the PLS loadings plot showed that the important variables in the spectral region came from the absorption maxima related to the amide bands at 1660 and 1550 cm−1 and amine band at 1600 cm−1. IR-PLS results were comparable to the results obtained by potentiometric titration. IR-PLS results were found to be more precise and rugged compared to the usual IR absorbance ratio method. This is consistent with the fact that IR spectral resolution is not really high and that the absorption at a single wavelength is influenced by other factors like hydrogen bonding and the presence of water.
2012
Ian Ken D. Dimzon; Jürgen Ebertb; Thomas P. Knepper
The interaction of chitosan and olive oil: Effects of degree of deacetylation and degree of polymerization Journal Article
In: Carbohydrate Polymers, vol. 92, no. 1, pp. 564-570, 2012.
Abstract | Links | Tags: chemometrics, chitosan, degree of deacetylation, degree of polymerization, oil-binding capacity, pls
@article{Dimzon2012,
title = {The interaction of chitosan and olive oil: Effects of degree of deacetylation and degree of polymerization},
author = {Ian Ken D. Dimzon and Jürgen Ebertb and Thomas P. Knepper},
url = {https://www.sciencedirect.com/science/article/abs/pii/S0144861712009526},
doi = {10.1016/j.carbpol.2012.09.035},
year = {2012},
date = {2012-09-28},
journal = {Carbohydrate Polymers},
volume = {92},
number = {1},
pages = {564-570},
abstract = {The combined effects of degree of deacetylation (DD) and degree of polymerization (DP) on the ability of chitosan to interact with olive oil was studied. The oil-binding test, a method that makes use of olive oil as a representative fat, was adopted as a measure of the interaction of chitosan and olive oil. The oil-binding capacities of twelve chitosan samples with DPs ranging from 470 to 1450 and DDs of 75% to 95% were determined. The oil-binding capacities were then correlated to the DD and DP using partial least squares (PLS) regression. The generated PLS model had a root mean square error of prediction (RMSEP) of 9.1%. Results indicated that oil-binding capacity is a function of DD more than of DP. For chitosan with DD at the interval 50% < DD < 90%, a negatively sloped linear correlation was obtained for DD and oil-binding capacity suggesting that hydrophobic intermolecular forces of attraction dominates the interaction of chitosan with olive oil. For chitosan with DD > 90%, the observed deviation from the linear correlation increased. In this interval, free fatty acid anions facilitate the interaction of chitosan and olive oil. Free fatty acids form a stable ionic interaction with the former and a strong hydrophobic interaction with the latter.},
keywords = {chemometrics, chitosan, degree of deacetylation, degree of polymerization, oil-binding capacity, pls},
pubstate = {published},
tppubtype = {article}
}
The combined effects of degree of deacetylation (DD) and degree of polymerization (DP) on the ability of chitosan to interact with olive oil was studied. The oil-binding test, a method that makes use of olive oil as a representative fat, was adopted as a measure of the interaction of chitosan and olive oil. The oil-binding capacities of twelve chitosan samples with DPs ranging from 470 to 1450 and DDs of 75% to 95% were determined. The oil-binding capacities were then correlated to the DD and DP using partial least squares (PLS) regression. The generated PLS model had a root mean square error of prediction (RMSEP) of 9.1%. Results indicated that oil-binding capacity is a function of DD more than of DP. For chitosan with DD at the interval 50% < DD < 90%, a negatively sloped linear correlation was obtained for DD and oil-binding capacity suggesting that hydrophobic intermolecular forces of attraction dominates the interaction of chitosan with olive oil. For chitosan with DD > 90%, the observed deviation from the linear correlation increased. In this interval, free fatty acid anions facilitate the interaction of chitosan and olive oil. Free fatty acids form a stable ionic interaction with the former and a strong hydrophobic interaction with the latter.
Ian Ken D. Dimzon; Thomas P. Knepper
MALDI–TOF MS for Characterization of Synthetic Polymers in Aqueous Environment Book Chapter
In: Fernandez-Alba, Amadeo R. (Ed.): TOF-MS within Food and Environmental Analysis: Comprehensive Analytical Chemistry, vol. 58, pp. 307-338, Elsevier B.V., 2012, ISBN: 978-0-444-53810-9.
Abstract | Links | Tags: average molecular weights, degradation, ESI, MALDI–TOF MS, matrix, polymer
@inbook{Dimzon2012b,
title = {MALDI–TOF MS for Characterization of Synthetic Polymers in Aqueous Environment},
author = {Ian Ken D. Dimzon and Thomas P. Knepper},
editor = {Amadeo R. Fernandez-Alba},
url = {https://www.sciencedirect.com/science/article/pii/B9780444538109000080},
doi = {10.1016/B978-0-444-53810-9.00008-0},
isbn = {978-0-444-53810-9},
year = {2012},
date = {2012-07-12},
booktitle = {TOF-MS within Food and Environmental Analysis: Comprehensive Analytical Chemistry},
journal = {Comprehensive Analytical Chemistry},
volume = {58},
pages = {307-338},
publisher = {Elsevier B.V.},
series = {TOF-MS within Food and Environmental Analysis},
abstract = {Polymers are large molecules composed of repeating monomer units. Variations in the composition and number of monomers, average size, distribution, microstructure, and the functional groups attached to the basic units create thousands of different polymer substances with a wide range of physicochemical properties and suit a variety of uses. In the recent years, time-of-flight mass spectrometry (TOF MS), especially the tandem with matrix-assisted laser desorption ionization (MALDI), plays a complimentary but vital role in polymer characterization. The mass spectrum provides a wealth of data regarding the structure, composition, and functionality of the individual polymer specie. This unique information from MS is necessary in elucidating structure–property–activity relations. The use of MALDI–TOF MS in polymer analysis can be extended to study the fate and degradation of the large molecules in aqueous environment.},
keywords = {average molecular weights, degradation, ESI, MALDI–TOF MS, matrix, polymer},
pubstate = {published},
tppubtype = {inbook}
}
Polymers are large molecules composed of repeating monomer units. Variations in the composition and number of monomers, average size, distribution, microstructure, and the functional groups attached to the basic units create thousands of different polymer substances with a wide range of physicochemical properties and suit a variety of uses. In the recent years, time-of-flight mass spectrometry (TOF MS), especially the tandem with matrix-assisted laser desorption ionization (MALDI), plays a complimentary but vital role in polymer characterization. The mass spectrum provides a wealth of data regarding the structure, composition, and functionality of the individual polymer specie. This unique information from MS is necessary in elucidating structure–property–activity relations. The use of MALDI–TOF MS in polymer analysis can be extended to study the fate and degradation of the large molecules in aqueous environment.
2011
Fabian M. Dayrit; Ian Ken D. Dimzon; Melodina F. Valde; Jaclyn Elizabeth R. Santos; Mark Joseph Garrovillas; Blanca J. Villarino
Quality characteristics of virgin coconut oil: Comparisons with refined coconut oil Journal Article
In: Pure & Applied Chemistry, vol. 83, no. 9, pp. 1789-1799, 2011.
Abstract | Links | Tags: 31P NMR, food chemistry, headspace solid-phase microextraction/gas chromatography mass spectrometry (SPME/GCMS), sensory analysis, virgin coconut oil (VCO)
@article{Dayrit2011,
title = {Quality characteristics of virgin coconut oil: Comparisons with refined coconut oil},
author = {Fabian M. Dayrit and Ian Ken D. Dimzon and Melodina F. Valde and Jaclyn Elizabeth R. Santos and Mark Joseph Garrovillas and Blanca J. Villarino},
url = {https://www.degruyter.com/document/doi/10.1351/PAC-CON-11-04-01/html},
doi = {10.1351/PAC-CON-11-04-01},
year = {2011},
date = {2011-08-11},
journal = {Pure & Applied Chemistry},
volume = {83},
number = {9},
pages = {1789-1799},
abstract = {Virgin coconut oil (VCO) is a vegetable oil that is extracted from fresh coconut meat and is processed using only physical and other natural means. VCO was compared to refined, bleached, and deodorized coconut oil (RCO) using standard quality parameters, 31 P nuclear magnetic resonance (NMR) spectroscopy, and headspace solid-phase micro - extraction/gas chromatography mass spectrometry (SPME/GCMS). VCO tends to have higher free fatty acids (FFAs), moisture, and volatile matter and lower peroxide value than RCO. However, the range of values overlap and no single standard parameter alone can be 31 used to differentiate VCO from RCO. Using 31P NMR, VCO and RCO can be distinguished in terms of the total amount of diglycerides: VCO showed an average content (w/w %) of 1.55, whereas RCO gave an average of 4.10. There was no overlap in the values found for individual VCO and RCO samples. There are four common methods of producing VCO: expeller (EXP), centrifuge (CEN), and fermentation with and without heat. VCO products prepared using these four methods could not be differentiated using standard quality parameters. Sensory analysis showed that VCO produced by fermentation (with and without heat) could be distinguished from those produced using the EXP and CEN methods; this sensory differentiation correlated with the higher levels of acetic acid and octanoic acid in the VCO produced by fermentation. Studies on physicochemical deterioration of VCO showed that VCO is stable to chemical and photochemical oxidation and hydrolysis. VCO is most susceptible to microbial attack, which leads to the formation of various organic acids, in particular, lactic acid. However, at moisture levels below 0.06 %, microbial action is significantly lessened.},
keywords = {31P NMR, food chemistry, headspace solid-phase microextraction/gas chromatography mass spectrometry (SPME/GCMS), sensory analysis, virgin coconut oil (VCO)},
pubstate = {published},
tppubtype = {article}
}
Virgin coconut oil (VCO) is a vegetable oil that is extracted from fresh coconut meat and is processed using only physical and other natural means. VCO was compared to refined, bleached, and deodorized coconut oil (RCO) using standard quality parameters, 31 P nuclear magnetic resonance (NMR) spectroscopy, and headspace solid-phase micro - extraction/gas chromatography mass spectrometry (SPME/GCMS). VCO tends to have higher free fatty acids (FFAs), moisture, and volatile matter and lower peroxide value than RCO. However, the range of values overlap and no single standard parameter alone can be 31 used to differentiate VCO from RCO. Using 31P NMR, VCO and RCO can be distinguished in terms of the total amount of diglycerides: VCO showed an average content (w/w %) of 1.55, whereas RCO gave an average of 4.10. There was no overlap in the values found for individual VCO and RCO samples. There are four common methods of producing VCO: expeller (EXP), centrifuge (CEN), and fermentation with and without heat. VCO products prepared using these four methods could not be differentiated using standard quality parameters. Sensory analysis showed that VCO produced by fermentation (with and without heat) could be distinguished from those produced using the EXP and CEN methods; this sensory differentiation correlated with the higher levels of acetic acid and octanoic acid in the VCO produced by fermentation. Studies on physicochemical deterioration of VCO showed that VCO is stable to chemical and photochemical oxidation and hydrolysis. VCO is most susceptible to microbial attack, which leads to the formation of various organic acids, in particular, lactic acid. However, at moisture levels below 0.06 %, microbial action is significantly lessened.
Ian Ken D. Dimzon; Melodina F. Valde; Jaclyn Elizabeth R. Santos; Mark Joseph Garrovillas; Henson M. Dejarme; Jo Margarette W. Remollo; Fabian M. Dayrit
Physico-Chemical and Microbiological Parameters in the Deterioration of Virgin Coconut Oil Journal Article
In: Philippine Journal of Science, vol. 140, no. 1, pp. 89-103, 2011, ISSN: 0031-7683.
Abstract | Links | Tags: hydrolysis, microbial deterioration, oxidation, virgin coconut oil
@article{Dimzon2011,
title = {Physico-Chemical and Microbiological Parameters in the Deterioration of Virgin Coconut Oil},
author = {Ian Ken D. Dimzon and Melodina F. Valde and Jaclyn Elizabeth R. Santos and Mark Joseph Garrovillas and Henson M. Dejarme and Jo Margarette W. Remollo and Fabian M. Dayrit},
url = {https://philjournalsci.dost.gov.ph/home-1/33-vol-140-no-1-june-2011/439-physico-chemical-and-microbiological-parameters-in-the-deterioration-of-virgin-coconut-oil},
issn = {0031-7683},
year = {2011},
date = {2011-06-01},
journal = {Philippine Journal of Science},
volume = {140},
number = {1},
pages = {89-103},
abstract = {The deterioration of virgin coconut oil (VCO) due to physico-chemical oxidation and hydrolysis and microbiological processes was studied. The physico-chemical oxidation of VCO in the air at room temperature was negligible. Oxidation of VCO was observed only in the presence of air, UV radiation, ferric ion (Fe3+), and high free fatty acid (FFA) content. Chemical hydrolysis was performed at varying moisture levels and temperatures. The rate of hydrolysis to produce FFAs was measured using 31P NMR under conditions of saturated water (0.22%) and 80°C was found to be 0.066 µmol/g-hr (expressed as lauric acid). At 0.084% moisture and 80°C, the rate of FFA formation was found to be 0.008 µmol/g-hr. The microbial decomposition of VCO was determined after four days of incubation at 37°C. At low moisture levels (<0.06%), VCO was stable to microbial decomposition. However, at higher moisture levels, there was an increase in the formation of organic acids, in particular, lactic acid, dodecanoic acid, succinic acid, acetic acid, and fumaric acid, indicating that microbial action had occurred. The most important conditions that influence the physico-chemical and microbial degradation of VCO are moisture, temperature, and the presence of microorganisms. These degradation processes can be minimized if the moisture level is maintained below 0.06%.},
keywords = {hydrolysis, microbial deterioration, oxidation, virgin coconut oil},
pubstate = {published},
tppubtype = {article}
}
The deterioration of virgin coconut oil (VCO) due to physico-chemical oxidation and hydrolysis and microbiological processes was studied. The physico-chemical oxidation of VCO in the air at room temperature was negligible. Oxidation of VCO was observed only in the presence of air, UV radiation, ferric ion (Fe3+), and high free fatty acid (FFA) content. Chemical hydrolysis was performed at varying moisture levels and temperatures. The rate of hydrolysis to produce FFAs was measured using 31P NMR under conditions of saturated water (0.22%) and 80°C was found to be 0.066 µmol/g-hr (expressed as lauric acid). At 0.084% moisture and 80°C, the rate of FFA formation was found to be 0.008 µmol/g-hr. The microbial decomposition of VCO was determined after four days of incubation at 37°C. At low moisture levels (<0.06%), VCO was stable to microbial decomposition. However, at higher moisture levels, there was an increase in the formation of organic acids, in particular, lactic acid, dodecanoic acid, succinic acid, acetic acid, and fumaric acid, indicating that microbial action had occurred. The most important conditions that influence the physico-chemical and microbial degradation of VCO are moisture, temperature, and the presence of microorganisms. These degradation processes can be minimized if the moisture level is maintained below 0.06%.
2007
Fabian M. Dayrit; Olivia Erin M. Buenafe; Edward T. Chainani; Ian Mitchelle S. de Vera; Ian Ken D. Dimzon; Estrella G. Gonzales; Jaclyn Elizabeth R. Santos
In: Philippine Journal of Science, vol. 136, no. 2, pp. 119-129, 2007, ISSN: 0031-7683.
Abstract | Links | Tags: % fatty acid composition, % moisture by Karl Fischer titration, % volatile matter at 120 ºC, copra oil, iodine value, peroxide value, principal components analysis (PCA), refined, bleached and deodorized coconut oil (RBD CNO), virgin coconut oil (VCO)
@article{Dayrit2007,
title = {Standards for essential composition and quality factors of commercial virgin coconut oil and its differentiation from RBD coconut oil and copra oil},
author = {Fabian M. Dayrit and Olivia Erin M. Buenafe and Edward T. Chainani and Ian Mitchelle S. de Vera and Ian Ken D. Dimzon and Estrella G. Gonzales and Jaclyn Elizabeth R. Santos},
url = {https://philjournalsci.dost.gov.ph/home-1/26-vol-136-no-2-december-2007/346-standards-for-essential-composition-and-quality-factors-of-commercial-virgin-coconut-oil-and-its-differentiation-from-rbd-coconut-oil-and-copra-oil},
issn = {0031-7683},
year = {2007},
date = {2007-12-01},
journal = {Philippine Journal of Science},
volume = {136},
number = {2},
pages = {119-129},
abstract = {Commercial samples of virgin coconut oil (VCO), refined, bleached and deodorized coconut oil (RBD CNO), and copra oil were analyzed using standard chemical parameters: gas chromatography (GC) of the fatty acid methyl esters (FAME), % moisture by Karl Fischer titration, % volatile matter at 120° C, % free fatty acid, iodine value, peroxide value, and microbial contamination. Principal components analysis (PCA) of the GC-FAME results indicates that the various samples cannot be differentiated by their fatty acid composition, indicating that the fatty acid profile is not affected by the processing method. No trans-fatty acid was detected in all samples down to 0.01% (w/w) detection limit. VCO can be differentiated from RBD CNO and copra oil using the following tests: % moisture by Karl Fischer, % volatile matter volatile at 120° C, and peroxide value.},
keywords = {% fatty acid composition, % moisture by Karl Fischer titration, % volatile matter at 120 ºC, copra oil, iodine value, peroxide value, principal components analysis (PCA), refined, bleached and deodorized coconut oil (RBD CNO), virgin coconut oil (VCO)},
pubstate = {published},
tppubtype = {article}
}
Commercial samples of virgin coconut oil (VCO), refined, bleached and deodorized coconut oil (RBD CNO), and copra oil were analyzed using standard chemical parameters: gas chromatography (GC) of the fatty acid methyl esters (FAME), % moisture by Karl Fischer titration, % volatile matter at 120° C, % free fatty acid, iodine value, peroxide value, and microbial contamination. Principal components analysis (PCA) of the GC-FAME results indicates that the various samples cannot be differentiated by their fatty acid composition, indicating that the fatty acid profile is not affected by the processing method. No trans-fatty acid was detected in all samples down to 0.01% (w/w) detection limit. VCO can be differentiated from RBD CNO and copra oil using the following tests: % moisture by Karl Fischer, % volatile matter volatile at 120° C, and peroxide value.
Fabian M. Dayrit; Olivia Erin M. Buenafe; Edward T. Chainani; Ian Mitchelle S. de Vera; Ian Ken D. Dimzon; Estrella G. Gonzales; Jaclyn Elizabeth R. Santos
Essential quality parameters of commercial virgin coconut oil Journal Article
In: Cord, vol. 23, no. 1, pp. 71-80, 2007.
@article{Dayrit2007b,
title = {Essential quality parameters of commercial virgin coconut oil},
author = {Fabian M. Dayrit and Olivia Erin M. Buenafe and Edward T. Chainani and Ian Mitchelle S. de Vera and Ian Ken D. Dimzon and Estrella G. Gonzales and Jaclyn Elizabeth R. Santos},
url = {https://library.apccsec.org/paneladmin/doc/20170827054843Fabian%20M.%20Dayrit.pdf},
year = {2007},
date = {2007-01-01},
journal = {Cord},
volume = {23},
number = {1},
pages = {71-80},
abstract = {Chemical analyses conducted on commercial samples of virgin coconut oil (VCO) produced by four different methods gave the following ranges of values: % Fatty acid composition: C6: 0.24 to 0.49%; C8: 4.15 to 8.30%; C10: 4.27 to 5.75%; C12: 46.0 to 52.6%; C14: 16.0 to 19.7%; C16: 7.65 to 10.1%; C18: 2.86 to 4.63%; C18:1: 5.93 to 8.53%; C18:2: 1.00 to 2.16%; %moisture by Karl Fischer: 0.05 to 0.12%; %matter volatile at 120 0C: 0.12 to 0.18%; %free fatty acids as lauric acid: 0.042 to 0.329%; and peroxide value: none detected to 1.40. The tests for %moisture by Karl Fischer and %matter volatile at 120 0C can be used to differentiate VCO from and refined, bleached and deodorized coconut oil (RBD CNO). No trans-fatty acid was detected in both VCO and RBD CNO down to 0.01% (w/w) detection limit.},
keywords = {-},
pubstate = {published},
tppubtype = {article}
}
Chemical analyses conducted on commercial samples of virgin coconut oil (VCO) produced by four different methods gave the following ranges of values: % Fatty acid composition: C6: 0.24 to 0.49%; C8: 4.15 to 8.30%; C10: 4.27 to 5.75%; C12: 46.0 to 52.6%; C14: 16.0 to 19.7%; C16: 7.65 to 10.1%; C18: 2.86 to 4.63%; C18:1: 5.93 to 8.53%; C18:2: 1.00 to 2.16%; %moisture by Karl Fischer: 0.05 to 0.12%; %matter volatile at 120 0C: 0.12 to 0.18%; %free fatty acids as lauric acid: 0.042 to 0.329%; and peroxide value: none detected to 1.40. The tests for %moisture by Karl Fischer and %matter volatile at 120 0C can be used to differentiate VCO from and refined, bleached and deodorized coconut oil (RBD CNO). No trans-fatty acid was detected in both VCO and RBD CNO down to 0.01% (w/w) detection limit.
Fabian M. Dayrit; Olivia Erin M. Buenafe; Edward T. Chainani; Ian Mitchelle S. de Vera; Ian Ken D. Dimzon; Estrella G. Gonzales; Jaclyn Elizabeth R. Santos
Studies on Standards for Commercial Virgin Coconut Oil Proceedings
National Academy of Science and Technology, 2007, ISSN: 1655-4299.
Abstract | Links | Tags: % fatty acid composition, Asia-Pacific Coconut Community (APCC), Codex Alimentarius, iodine value, standards, virgin coconut oil (VCO)
@proceedings{Dayrit2007c,
title = {Studies on Standards for Commercial Virgin Coconut Oil},
author = {Fabian M. Dayrit and Olivia Erin M. Buenafe and Edward T. Chainani and Ian Mitchelle S. de Vera and Ian Ken D. Dimzon and Estrella G. Gonzales and Jaclyn Elizabeth R. Santos},
url = {http://nast.ph/images/pdf%20files/Publications/Monograph%20Series/NAST%20Monograph%20Series%2014.pdf#page=34},
issn = {1655-4299},
year = {2007},
date = {2007-01-01},
journal = {Virgin Coconut Oil: State of the Art},
pages = {19-35},
publisher = {National Academy of Science and Technology},
series = {14},
abstract = {A minimum set of analytical methods is recommended for the differentiation of virgin coconut oil (VCO) from refined, bleached and deodorized coconut oil (RBD CNO): % fatty acid composition,% moisture by Karl Fischer (0.10%), % volatile matter at 120°C (0.10-0.20%), % free fatty acids as lauric acid (0.2%), peroxide value (3 meq/kg), and microbial contamination by colony forming units (<10 cfu/mL). The% fatty acid composition was determined using an internal standard and molecular weight correction from the fatty acid methyl ester to the fatty acid. This method yields absolute amounts of fatty acid in the oil. The absolute amount of oleic acid and linoleic acid can be used to replace the iodine value. Principal components analysis of the fatty acid composition indicates that it is not affected by the processing method.},
keywords = {% fatty acid composition, Asia-Pacific Coconut Community (APCC), Codex Alimentarius, iodine value, standards, virgin coconut oil (VCO)},
pubstate = {published},
tppubtype = {proceedings}
}
A minimum set of analytical methods is recommended for the differentiation of virgin coconut oil (VCO) from refined, bleached and deodorized coconut oil (RBD CNO): % fatty acid composition,% moisture by Karl Fischer (0.10%), % volatile matter at 120°C (0.10-0.20%), % free fatty acids as lauric acid (0.2%), peroxide value (3 meq/kg), and microbial contamination by colony forming units (<10 cfu/mL). The% fatty acid composition was determined using an internal standard and molecular weight correction from the fatty acid methyl ester to the fatty acid. This method yields absolute amounts of fatty acid in the oil. The absolute amount of oleic acid and linoleic acid can be used to replace the iodine value. Principal components analysis of the fatty acid composition indicates that it is not affected by the processing method.