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An UPLC–MS/MS method based on matrix solid-phase dispersion (MSPD) was developed for the determination of chloramphenicol (CAP), thiamphenicol (TAP) and florfenicol (FF) in fish muscle. Muscle tissue was blended with octadecylsilyl-derivatized silica (C 18 ). A column made from the C 18 /muscle tissue matrix was washed with n-hexane, after which CAP was eluted with acetonitrile/water (50:50, v/v) and partitioned into ethyl acetate. The final extract was evaporated, and reconstituted into methanol/water (10:90, v/v) for the analysis of UPLC–MS/MS. The correlation coefficient ( r 2 ) with each matrix-matched calibration curve is higher than 0.999. CC α and CC β of the fenicols upon the method were ranged from 0.02 to 0.06 μg kg −1 and 0.11–0.16 μg kg −1 respectively. At the fortified levels, mean recoveries of the three compounds were ranged from 84.2% to 99.8%, and the RSDs were lower than 12%. The method was accurate and reproducible, being successfully applied to the monitoring of CAP, TAP and FF in fish samples obtained from the Chinese market. [ABSTRACT FROM AUTHOR]

A quantificational method for 7 phthalate esters in non-alcoholic beverages was developed. Dimethyl phthalate, di-ethyl phthalate, di-propyl phthalate (DPP), di-butyl phthalate (DBP), benzyl butyl phthalate, di-(2-ethylhexyl) phthalate (DEHP), and di-octyl phthalate (DOP) were extracted from non-alcoholic beverages with the optimized solid-phase extraction method, and quantification was achieved by gas chromatography-mass spectrometry with isotope internal standard of d-di-(2-ethylhexyl) phthalate (DEHP-d). The inter-day method repeatability (RSD) was 8-13 %, whereas the intra-day method repeatability (RSD) was 9-15 %. The mean spiking recoveries were 84-105 %. A wide variety of phthalate concentrations was observed in 48 non-alcoholic beverages. DEHP was the most abundant phthalate compound followed by DBP, DPP, and DOP. DEHP was found in sport drinks (0.015-0.098 mg L), tea (0.016-0.123 mg L), coffee (0.028-0.159 mg L), and fruit juices (0.022-0.126 mg L). [ABSTRACT FROM AUTHOR]

Abstract: This report described a method for simultaneous determination of cyanuric acid (CYA) and melamine (MEL) in dairy products. The samples were extracted by a mixture of acetonitrile/water and cleaned by graphite carbon/strong cation exchange (CARB/SCX) mixed-mode solid phase extraction column. The CYA and MEL were derivatized with bis(trimethylsily1)trifluoroacetamide (BSTFA) containing 1% Trimethylchlorosilane (TMCS), and quantified with the internal standards of 15N3-cyanuric acid and 13C3-melamine by GC–MS. The results indicated that CARB/SCX mixed solid phase extraction column could be used for sample pretreatment. The fortification recoveries were 80.8–101.5%, and the relative standard deviations (RSDs) were 3.6–7.9%. The detection limits of CYA and MEL were 0.025mgkg−1 and 0.01mgkg−1 respectively. [Copyright &y& Elsevier]

Highlights: [•] A method for ethyl carbamate (EC) analysis was developed by GC–MS. [•] Diatomaceous earth solid-phase extraction (SPE) was used for purification. [•] In-house validation showed the limit of quantification (LOQ) was 5.0μg/kg. [•] A collaborative trial was carried out for further validation. [Copyright &y& Elsevier]