Determination of 60 Migrant Substances in Plastic Food Contact Materials by Vortex-Assisted Liquid-Liquid Extraction and GC-Q-Orbitrap HRMS

A GC-HRMS analytical method for the determination of 60 migrant substances, including aldehydes, ketones, phthalates and other plasticizers, phenol derivatives, acrylates, and methacrylates, in plastic food contact materials (FCM) has been developed and validated. The proposed method includes migration tests, according to Commission Regulation (EU) 10/2011, using four food simulants (A, B, C, and D1), followed by vortex-assisted liquid–liquid extraction (VA-LLE) and GC-Q-Orbitrap HRMS analysis in selected ion monitoring (SIM) mode, with a resolving power of 30,000 FWHM and a mass accuracy ≤5 ppm. The method was validated, showing satisfactory linearity (R2 ≥ 0.98 from 40 to 400 µg L−1), limits of quantification (40 µg L−1), precision (RSD, 0.6–12.6%), and relative recovery (81–120%). The proposed method was applied to the analysis of field samples, including an epoxy-coated tin food can, a drinking bottle made of Tritan copolyester, a disposable glass made of polycarbonate, and a baby feeding bottle made of polypropylene, showing that they were in compliance with the current European regulation regarding the studied substances.

Chloroform and Cognitive Function in the General Population of the US Elderly: A Cross-Sectional Study

Background Chloroform is a water disinfection by-product associated with hepatic, renal and neurotoxicity. High concentrations of chloroform are known to cause central nervous system depression; however, the association between blood chloroform levels and cognitive function in the general elderly population is unknown. In this study, we investigated the association between blood chloroform levels and cognitive function in the elderly US population (n=782). Methods We analyzed blood chloroform levels and cognitive function, as measured by the digit symbol substitution test (DSST), from the 2011-2012 and 2013-2014 National Health and Nutrition Examination Surveys (NHANES) for participants aged 60 years and older. Blood chloroform levels were measured using capillary gas chromatography and mass spectrometry with selected-ion monitoring detection and istotope-dilution. Results After adjusting for all covariates, increases in log-transformed blood chloroform levels were significantly associated with decreased DSST scores (β = -1.56, SE = 0.57, p-value 0.010). Compared with individuals in the lowest quartile of blood chloroform, the regression coefficients were significantly lower among those in the second and third tertile (tertile 2 β = -3.00 (SE = 1.25, p-value 0.022); tertile 3 β = -4.05 (SE = 1.22, p-value 0.002)). After stratification by obesity status, increases in log-transformed chloroform levels showed borderline significant associations with decreased DSST scores among the obese (β = -1.71, SE = 0.85, p-value 0.052). Conclusions Our finding suggest a possible link between blood chloroform levels and cognitive function in the US elderly population.

GC/EI-MS method for the determination of phytosterols in vegetable oils

Sterols are a highly complex group of lipophilic compounds present in the unsaponifiable matter of virtually all living organisms. In this study, we developed a novel gas chromatography with mass spectrometry selected ion monitoring (GC/MS-SIM) method for the comprehensive analysis of sterols after saponification and silylation. A new referencing system was introduced by means of a series of saturated fatty acid pyrrolidides (FAPs) as internal standards. Linked with retention time locking (RTL), the resulting FAP retention indices (RIFAP) of the sterols could be determined with high precision. The GC/MS-SIM method was based on the parallel measurement of 17 SIM ions in four time windows. This set included eight molecular ions and seven diagnostic fragment ions of silylated sterols as well as two abundant ions of FAPs. Altogether, twenty molecular ions of C27- to C31-sterols with 0–3 double bonds were included in the final method. Screening of four common vegetable oils (sunflower oil, hemp oil, rapeseed oil, and corn oil) enabled the detection of 30 different sterols and triterpenes most of which could be identified. Graphical abstract

Method Development for the Control of Potential Genotoxic Impurities in Vigabatrin Using Gas Chromatography Techniques and Mass Spectroscopy Detector

Aim: To develop a sensitive headspace GC-MS method for the determination of potential genotoxic impurities in Vigabatrin. Place and Duration of Study: The study was performed in SIONC Pharmaceuticals, Visakhapatnam from June 2020 to March 2021. Methodology: The impurities were determined by selected ion monitoring mode using VF -WAXms (30 mts length, 0.25 mm internal diameter, 1.0 µ film thickness) column. Helium gas was used as carrier gas with a column flow of 1.0 mL/min. and injector temperature maintained at 220 0C. Oven Temperature, loop temperature and transfer line temperature were maintained in the head space at 70oC, 90oC and 100oC respectively. Results: The linearity of the method was proposed in the range of LOQ to 150 % for the genotoxic impurities by subjecting the data obtained to statistical analysis using linear regression model (r2 > 0.99). The method also gave acceptable recovery of all the four impurities at each level and was found to be accurate. The % RSD obtained in the method precision and intermediate precision were less than 11% depicting the precision of the method. The LOD and LOQ values were calculated based on the signal to noise ratio and are indicating the sensitivity of the method. The specificity of the method was checked for blank interference at the retention time of respective impurities. Conclusion: The results proved that the proposed headspace GC-MS method for the study of potential genotoxic impurities of Vigabatrin was sensitive, precise and accurate and could be routinely used in the quality control testing of the active pharmaceutical ingredient.

Quantification of a New Antifungal Drug Based on 1,3,4-Thiadiazole by HPLC-ESI/MS: Method Development, Validation and Pharmacokinetic Application

The high sensitive HPLC-ESI/MS method for quantitative determination of a new antifungal drug – 2-[(1Z)-1-(3,5-diphenyl-1,3,4-thiadiazol-2(3Н)-ylidene)methyl]-3,5-diphenyl-1,3,4-thiadiazol-3-ium chloride (TDZ) – was developed and fully validated. TDZ was separated from plasma and urine samples by acetonitrile deproteinization and extraction without time-consuming sample preparation. The reversed-phase high-performance liquid chromatography on Kromasil 100–3.5 C8 column of TDZ in isocratic elution mode using 0.03% trifluoroacetic acid : acetonitrile (65:35, v/v) at a flow rate of 0.2 mL min−1 was performed. Determination of TDZ was carried out by a positive electrospray ionization in a selected ion monitoring mode for [M+]=489 m/z. The method of absolute calibration was used for quantification of TDZ in two concentrations ranges: 100–2500 pg mL−1 and 2500–30 000 pg mL−1. The established method showed a good linearity (R=0.999 for both ranges), the limits of determination and quantification were 50 and 100 pg mL−1, respectively. The Intra- and Inter-day precision values were measured by t-Distribution and Fisher′s Exact Test and were in accordance with the regulatory guidance. Low matrix effects and good recovery were found for TDZ. The present method was successfully applied to determine the pharmacokinetic parameters of TDZ by means of intravenous and oral administrations to rats at 5.0 mg kg−1 and 10.0 mg kg−1, respectively.

Identification of Fish Species and Toxins Implicated in a Snapper Food Poisoning Event in Sabah, Malaysia, 2017

In the coastal countries of Southeast Asia, fish is a staple diet and certain fish species are food delicacies to local populations or commercially important to individual communities. Although there have been several suspected cases of ciguatera fish poisoning (CFP) in Southeast Asian countries, few have been confirmed by ciguatoxins identification, resulting in limited information for the correct diagnosis of this food-borne disease. In the present study, ciguatoxin-1B (CTX-1B) in red snapper (Lutjanus bohar) implicated in a CFP case in Sabah, Malaysia, in December 2017 was determined by single-quadrupole selected ion monitoring (SIM) liquid chromatography/mass spectrometry (LC/MS). Continuous consumption of the toxic fish likely resulted in CFP, even when the toxin concentration in the fish consumed was low. The identification of the fish species was performed using the molecular characterization of the mitochondrial cytochrome c oxidase subunit I gene marker, with a phylogenetic analysis of the genus Lutjanus. This is the first report identifying the causative toxin in fish-implicated CFP in Malaysia.

Effective Extraction of Limonene and Hibaene from Hinoki (Chamaecyparis obtusa) Using Ionic Liquid and Deep Eutectic Solvent

The essential oils of hinoki (Chamaecyparis obtusa) leaves have anti-bacterial, anti-fungal, and relaxation properties that are likely associated with the major components such as sabinene, α-terpinyl acetate, limonene, elemol, myrcene, and hibaene. The present study describes the use of a cellulose-dissolving ionic liquid (IL) [C2mim][(MeO)(H)PO2] and low-toxicity solvents called betaine-based deep eutectic solvents (DESs) for the efficient extraction of hinoki essential oils. As a control method, organic solvent extraction was performed using either hexane, ethyl acetate (EtOAc), or acetone at 30 °C for 1 h. Both the experimental and control methods were conducted under the same conditions, which relied on partial dissolution of the leaves using the IL and DESs before partitioning the hinoki oils into the organic solvent for analysis. Quantitative analysis was performed using gas chromatography–mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. The results indicated that extraction using the [C2mim][(MeO)(H)PO2]/acetone bilayer system improved the yields of limonene and hibaene, 1.5- and 1.9-fold, respectively, when compared with the control method. In addition, extraction using betaine/l-lactic acid (molar ratio 1:1) gave the greatest yields for both limonene and hibaene, 1.3-fold and 1.5-fold greater, respectively, than when using an organic solvent. These results demonstrate the effective extraction of essential oils from plant leaves under conditions milder than those needed for the conventional method. The less toxic and environmentally begin DESs for the extraction are also applicable to the food and cosmetic industries.

Development and Validation of Ecofriendly HPLC-MS Method for Quantitative Assay of Amoxicillin, Dicloxacillin, and Their Official Impurity in Pure and Dosage Forms

Novel, accurate, selective, and rapid high-performance liquid chromatography mass spectrometry method was developed for simultaneous analysis of amoxicillin trihydrate, dicloxacillin sodium, and their official impurity 6-aminopenicillanic acid. The chromatographic separation was carried out by applying the mixture on a C18 column (3.5 µm ps, 100 mm × 4.6 mm id) using acetonitrile:water (65 : 35 by volume) as a mobile phase within only 4 min. The quantitative analysis was executed using single quadrupole mass spectrometer in which electrospray ionization, selected ion monitoring, and negative mode were operated. The retention times were 1.61, 2.54, and 3.50 mins for amoxicillin, 6-aminopenicillanic acid, and dicloxacillin, respectively. The method was validated in linear ranges of 2–28 µg mL−1, 2–35 µg mL−1, and 1–10 µg mL−1 for amoxicillin, dicloxacillin, and 6-aminopenicillanic acid, respectively. The results obtained from the suggested HPLC/MS were statistically compared with those obtained from the reported HPLC method, where no significant difference appeared respecting accuracy and precision. According to the analytical eco-scale assessment method, the proposed method was proved to be greener than the reported one, where the analysis time and the amount of the wasted effluent decreased.