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Xu D.,Inspection and Quarantine Technology Center | Deng X.,Animal Plants and Foods Inspection and Quarantine Technical Center | Fang E.,Inspection and Quarantine Technology Center | Zheng X.,Inspection and Quarantine Technology Center | And 5 more authors.
Journal of Chromatography A | Year: 2014

A rapid and sensitive method was developed for the determination of 23 phthalates in food samples including milk-based products, distilled liquor, wine, beverage, grain, meat, oil, biscuit (cookie), and canned food by liquid chromatography tandem mass spectrometry (LC-MS/MS). Liquid samples were exacted by acetonitrile, while solid samples were prepared by QuEChERS or glass-based SPE methods. The 23 phthalates were separated on Poroshell 120 EC-C18 column and followed by positive electrospray ionization as well as multi-reaction monitoring provided by a triple-quadrupole tandem mass spectrometer. To reduce contamination, the plastic materials were avoided in sample handling and preparation The LODs were between 0.8 and 15μgkg-1 and LOQs were between 10 and 100μgkg-1. By using different concentrations: 100, 500, and 1000μgkg-1) for DINP and DIDP; 50, 100, and 1000μgkg-1 for other 21 phthalate compounds, the spiked recoveries were within 75.5-115.2% and the relative standard deviations (RSDs) were in the range of 3.2-18.9%. The proposed protocol was then applied to the analysis of 623 real samples collected from the two sides of the Taiwan Straits, and the DEHP was found in almost all samples tested in this study, with levels ranging from 0.02 to 2685mgkg-1. The present study demonstrated a rapid, sensitive, and accurate method for determining 23 phthalates in foodstuffs. © 2013 Elsevier B.V. Source


Ren Z.,Agricultural University of Hebei | Ren Z.,Chinese Academy of Inspection and Quarantine | Ai X.,Chinese Academy of Inspection and Quarantine | Ai X.,Huazhong Agricultural University | And 4 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2015

An analytical method for the determination of catechol in tobacco by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) has been developed. A Sep-Park-C18 solid phase extraction cartridge was used for the enrichment of the analyte for HPLC-MS/MS analysis. The mobile phase was methanol-0.2% (v/v) formic acid with gradient elution. The sample was analyzed by HPLC-MS/MS in the ESI-scanning mode with multi-reaction monitoring (MRM) for qualitative and quantitative analyses. The linear range of calibration curve was 0.5-200 μg/kg with good correlation coefficients (r2 = 0.998 9). The recoveries of catechol spiked in three levels were in the range of 83.1%-98.6%, with the relative standard deviations of 1.9%-5.8%. This method was initially applied to the research of catechol as a flavor additive in six retail tobacco samples and proved to be accurate, sensitive, convenient and practical. The analyte was found in the six retail tobacco samples, and in some cases, the presence of quite high concentrations of catechol in tobacco should be a matter of concern. Source


Zhou W.-E.,Chinese Academy of Inspection and Quarantine | Zhou W.-E.,Guangxi University | Zhang Y.,Chinese Academy of Inspection and Quarantine | Li Y.,Guangxi University | And 7 more authors.
Journal of Chromatography A | Year: 2016

A novel, rapid and simple analytical method was developed for the quantitative determination of crocin, crocetin and geniposide in soft drink, pastry and instant noodles. The solid samples were relatively homogenized into powders and fragments. The gardenia yellow colorants were successively extracted with methanol using ultrasound-assisted extraction. The analytes were quantitatively measured in the extracts by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. High correlation coefficients (r2 > 0.995) of crocin, crocetin and geniposide were obtained within their linear ranges respectively (50-1000 ng/mL, 50-1000 ng/mL, 15-240 ng/mL) by external standard method. The limits of detection (LODs) were 0.02 μg/g for crocin, 0.01 μg/g for crocetin and 0.002 μg/g for geniposide. And the limits of quantitation (LOQs) were in the ranges of 0.05-0.45 μg/g for crocin, and in the ranges of 0.042-0.32 μg/g for crocetin, and in the ranges of 0.02-0.15 μg/g for geniposide in soft drink, pastry and instant noodles samples. The average recoveries of crocin, crocetin and geniposide ranged from 81.3% to 117.6% in soft drink, pastry and instant noodles. The intra- and inter-day precisions were respectively in the range of 1.3-4.8% and 1.7-11.8% in soft drink, pastry and instant noodle. The developed methods were successfully validated and applied to the soft drink, pastry, and instant noodles collected from the located market in Beijing from China. Crocin, crocetin and geniposide were detected in the collected samples. The average concentrations ranged from 0.84 to 4.20 mg/g for crocin, and from 0.62 to 3.11 mg/g for crocetin, and from 0.18 to 0.79 mg/g for gardenia in various food samples. The method can provide evidences for government to determine gardenia yellow pigments and geniposide in food. © 2016 Elsevier B.V. Source


Guo B.,Hunan Normal University | Wang M.,Hunan Academy of Inspection and Quarantine | Liu Y.,Hunan Normal University | Zhou J.,Hunan Normal University | And 5 more authors.
Journal of Agricultural and Food Chemistry | Year: 2015

A new analytical strategy was developed that integrates a generic sample preparation into a liquid chromatography-multistage ion trap/time-of-flight mass spectrometry (LC-IT(MSn)/TOF), allowing for large-scale screening and qualitative confirmation of wide-scope illegal adulterants in different food matrices. Samples were pretreated by a fast single-tube multifunction extraction for accurate multistage mass measurement on the hybrid LC-IT/TOF system. A qualitative validation performed for over 500 analyte-matrix pairs showed the method can reduce most of the matrix effects and achieve a lower limit of confirmation at 0.1 mg/kg for 73% of the target compounds. A unique combination of dual-polarity detection, retention time, isotopic profile, and accurate MSn spectra enables more comprehensive and precise confirmation, based on the multiparameter matching by automated library searching against the user-created database. Finally, the applicability of this LC-IT(MSn)/TOF-based screening procedure for discriminating coeluting isobars, identifying nontarget adulterants, and even tentatively elucidating unexpected species in real samples is demonstrated. © 2015 American Chemical Society. Source


Li R.,Zhongshan Entry Exit Inspection and Quarantine Bureau | Bo Y.,Hunan Academy of Inspection and Quarantine | Bo Y.,Jinan University | Lu J.,Zhongshan Entry Exit Inspection and Quarantine Bureau | And 3 more authors.
Chinese Journal of Chromatography (Se Pu) | Year: 2016

An efficient method using gas chromatography-triple quadrupole mass spectrometry for the determination of 28 phthalate ester residues in bakery foods was established. The samples were extracted with ethyl acetate, and cleaned up with neutral alumina. The separation was performed on a TR-5MS capillary column (30 m×0.25 mm×0.25 μ m) by programmed temperature vaporization (PTV) with splitless mode. Meanwhile the identification and quantification were performed by GC-MS/MS in selected reaction monitoring (SRM) mode and using the internal standard method. The calibration curves of the 27 phthalate esters showed good linearities in the range of 0.05-10 mg/L, except diisononyl ortho-phthalate (DINP) which was in the range of 0.1-20 mg/L, with the correlation coefficients not less 0.9962. The limits of detection (LODs) were 0.1-9.8 μ g/kg and the limits of quantification (LOQs) were 0.4-32.6 μ g/kg. With the proposed method, the spiked recoveries were evaluated in four types of baked foods (bread, biscuits, cakes, stuffing) at low, medium and high concentrations. The results showed that the average recoveries of the 28 PAEs were in the range of 81.0%-117%, and the relative standard deviations (RSDs, n=6) were in the range of 1.3%-13.6%. The method was successfully applied in the investigation of the PAEs distribution in baked foods. The method is suitable for the determination of the 28 PAEs in baked foods with easy operation, high accuracy and precision. Source

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