Comparison of trapping efficiency of dicarbonyl trapping agents and reducing agents on reduction of furanoic compounds in commercially available soy sauce varieties.

This study has conducted to determine the concentration levels of furan, furfural and 2-methylfuran in the six commercially available soy sauce varieties by an optimized Gas Chromatography Tripple Quadruple Mass Spectrometry. The extraction of analytes was performed by solid phase microextraction using 50/30 µm CAR/DVB/PDMS fibre in 25 min with 20% NaCl concentration under 35 °C and separation was performed on HP5-MS column. Different concentration levels of furan, furfural and 2-methylfuran were determined which differed significantly at p < 0.05. A total of four metal ions (Iron sulphate, magnesium sulphate, calcium sulphate and sodium sulfite), ascorbic acid and natural antioxidants (epicatechin, epigalactocatechin and kempferol) were added in the soy sauce samples by simulating sterilization conditions. A higher reduction level was given by calcium sulphate with reduction upto 90.68%, 89.07% and 65.42% for furan, furfural and 2-methylfuran, respectively, in comparison with other metal ions. Since iron sulphate and ascorbic acid have triggered formation of furanoic compounds upto high levels instead of reduction. Moreover, from natural antioxidants, epicatechin and kemferol have provided more reduction levels around 89.66%, 90.14% and 78.75% for furan, furfural and 2-methylfuran, respectively by sterilization with catichen and 88.80%, 90.36% and 84.29% for furan, furfural and 2-methylfuran, respectively by sterilization with kempferol than epigalactocatechin. Moreover, this method was also validated in terms of sensitivity, recovery, relative standard deviation and LOD and LOQ for all analytes.

Targeted quantitation of furan fatty acids in edible oils by gas chromatography/triple quadrupole tandem mass spectrometry (GC-TQ/MS).

Furan fatty acids (FuFAs) have been recognized as beneficial food ingredients to human health. Herein, a targeted quantitation approach by gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-TQ/MS) was developed for the identification of FuFAs in common marine and other edible oils in multiple reaction monitoring (MRM) mode without any isolation and enrichment. The limit-of-quantitation (LOQ, 0.6 pg) was determined under the optimized parameters in MRM mode. Identification of FuFAs in common edible oils demonstrated that marine fish oils were concentrated sources of 9-(3-methyl-5-pentylfuran-2-yl)nonanoic acid (9M5), 11-(3,4-dimethyl-5-propylfuran-2-yl)undecanoic acid (11D3) and 11-(3,4-dimethyl-5-pentylfuran-2-yl)undecanoic acid (11D5). However, FuFAs were not identified in common plant oils. Additionally, 11D5 was identified in the lipids of Schizochytrium limacinum at a comparable level with that in marine fish oil. We believe that this protocol could facilitate the qualitative and quantitative analysis of FuFAs in food and biological samples.

Determination of fungicides in white grape bagasse by pressurized liquid extraction and gas chromatography tandem mass spectrometry.

Ultrasound-assisted extraction (UAE) and pressurized liquid extraction (PLE) followed by gas chromatography-triple quadrupole-mass spectrometry (GC TQ-MS) were used for the rapid determination of 11 fungicides (metalaxyl, cyprodinil, procymidone, iprovalicarb, myclobutanyl, kresoxim-methyl, benalaxyl, fenhexamide, tebuconazole, iprodione and dimethomorph) in white grape bagasse. The extractions were optimized on real non-spiked samples by means of experimental design and the optimal conditions were selected to achieve the method validation. The PLE procedure showed much higher efficiency than UAE for the target fungicides. Under the selected extraction conditions, PLE showed satisfactory linearity, repeatability and reproducibility. Recoveries for the majority of studied fungicides were higher than 80% with relative standard deviations (RSD) lower than 12%. Limits of detection (LODs) for GC TQ-MS were very low, at the sub ngg(-1) for the majority of the target fungicides, well below the European maximum residue limits (MRLs) for wine and table grapes, and vine leaves. Eighteen white grape bagasse samples were analyzed and nine out of eleven targets were detected in the samples. Seven of them were detected in more than 50% of the samples and most samples contained at least four of the target analytes. The most frequently found compounds were tebuconazole and dimethomorph with concentrations between 1.6-130 and 2.0-1788ngg(-1), respectively. Some samples showed high levels of many of the studied fungicides (high ngg(-1), even µgg(-1) for cyprodinil, fenhexamide, iprodione and dimethomorph), but all of them below the European maximum residue limits (MRLs) for wine grapes.