Profile of Volatile Organic Compounds (VOCs) from Cold-Processed and Heat-Treated Virgin Coconut Oil (VCO) Samples

Virgin coconut oil (VCO) can be prepared with or without heat. Fermentation and centrifuge processes can be done without the use of heat (cold process), while expelling involves heat due to friction. Volatile organic compounds (VOCs) from VCO samples prepared using these three methods were collected using solid phase microextraction (SPME) and analyzed using gas chromatography–mass spectrometry (GC-MS). Twenty-seven VCO samples from nine VCO producers were analyzed. The VOCs from refined, bleached, and deodorized coconut oil (RBDCO) were also obtained for comparison. Fourteen compounds were found to be common in more than 80% of the VCO samples analyzed. These included: Acetic acid; C6, C8, C10, C12, and C14 fatty acids, and their corresponding delta-lactones; and C8, C10 and C12 ethyl carboxylates. Fourteen minor VOCs were likewise detected which can be grouped into five types: Carboxylic acids (formic acid, butanoic acid, benzoic acid, and pentadecanoic acid), ketones (acetoin, 2-heptanone), an alcohol (ethanol), aldehydes (acetaldehyde, hexanal, benzaldehyde), esters (ethyl acetate, methyl tetradecanoate), and hydrocarbons (n-hexane and toluene). Five pyrazines were detected in expeller VCO. Various hydrocarbons from C5 to C14 were noted to be higher in old RBDCO and VCO samples. There were variations in the VOCs within each VCO process as each producer used different processing times, temperatures, and drying procedures. Principal components analysis (PCA) was able to group the samples according to the process used, but there were overlaps which may be due to variations in the specific procedures used by the manufacturers. These results may help VCO manufacturers control their production processes

High Resolution Mass Spectrometry of Polyfluorinated Polyether-Based Formulation

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

Quality characteristics of virgin coconut oil:Comparisons with refined coconut oil

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

Physico-Chemical and Microbiological Parameters in the Deterioration of Virgin Coconut Oil

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 (\u3c0.06%), 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 physicochemical 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%

Characterization of 3‑Aminopropyl Oligosilsesquioxane

The synthesis routes in the production of polysilsesquioxanes have largely relied upon <i>in situ</i> 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

Standards for essential composition and quality factors of commercial virgin coconut oil and its differentiation from RBD coconut oil and copra oil

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

Studies on Standards for Commercial Virgin Coconut Oil

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 (\u3c10 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

Essential quality parameters of commercial virgin coconut oil

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

Microextraction of polychlorinated biphenyls (PCBS) from soil samples

The standard method of polychlorinated biphenyl (PCB) analysis in soil samples requires Soxhlet extraction of gram amount of sample, considerable amounts of hazardous solvents, and a clean-up and extraction time of 3 days per sample. An efficient microextraction procedure has been developed for the trace quantitative analysis of PCBs in soil samples that will only necessitate a small fraction of the Soxhlet extraction requirements ad still achieve good recoveries for PCB congeners. The microextrcation procedures requires only 0.1g amount of sample and is relatively inexpensive extraction technique, which can be completed within 18 hours. The technique uses standard glassware and only minimal amount of solvent. In this work, parameters such as the type and amount of extracting solvent were evaluated. The congener-specific recoveries of the 20 target PCBs were compared using hexane and heptane as extracting solvents. When compared to the certified concentrations of the 20 congeners in the soil standard reference material (SRM) from the National Institute of Standards and Technology (NIST), the proposed microextraction method using heptane showed excellent recoveries for 10 of the congeners. The other 10 target congeners were found with other PCB congeners or contaminants. Moreover, the recoveries of the 2 surrogate internal standards, PCB #30 and 112, were also within the acceptable limit of ±30% even at 25 ng/g

Practical Application Guide for the Discovery of Novel PFAS in Environmental Samples Using High Resolution Mass Spectrometry

Background The intersection of the topics of high-resolution mass spectrometry (HRMS) and per- and polyfluoroalkyl substances (PFAS) bring together two disparate and complex subjects. Recently non-targeted analysis (NTA) for the discovery of novel PFAS in environmental and biological media has been shown to be valuable in multiple applications. Classical targeted analysis for PFAS using LC-MS/MS, though growing in compound coverage, is still unable to inform a holistic understanding of the PFAS burden in most samples. NTA fills at least a portion of this data gap. Objectives Entrance into the study of novel PFAS discovery requires identification techniques such as HRMS (e.g., QTOF and Orbitrap) instrumentation. This requires practical knowledge of best approaches depending on the purpose of the analyses. The utility of HRMS applications for PFAS discovery is unquestioned and will likely play a significant role in many future environmental and human exposure studies. Methods/Results PFAS have some characteristics that make them standout from most other chemicals present in samples. Through a series of tell-tale PFAS characteristics (e.g., characteristic mass defect range, homologous series and characteristic fragmentation patterns), and case studies different approaches and remaining challenges are demonstrated. Impact statement: The identification of novel PFAS via non-targeted analysis using high resolution mass spectrometry is an important and difficult endeavor. This synopsis document will hopefully make current and future efforts on this topic easier to perform for novice and experienced alike. The typical time devoted to NTA PFAS investigations (weeks to months or more) may benefit from these practical steps employed