A gas chromatography–tandem mass spectrometry (GC–MS/MS) method was developed for the first simultaneous identification and quantification of six pyrazole fungicides (furametpyr, rabenzazole, fluxapyroxad, penflufen, bixafen, and isopyrazam) in grape wine samples. The grape wine samples were first diluted with water, then purified by solid-phase extraction, and finally examined by GC–MS/MS in multiple reaction monitoring (MRM) mode. Matrix-matched calibration curves were used to correct the matrix effects. The limits of quantification (LOQs), calculated as 10 times the standard deviation, were 0.2–0.8 μg kg–1 for the six pyrazole fungicides. The average recoveries were in the range of 74.3–94.5%, with relative standard deviations (RSDs) below 5.8%, measured at three concentration levels. The proposed method is suitable for the simultaneous determination of six pyrazole fungicides in grape wine samples.

•Validamycin A LC–APCI–MS/MS analysis for the first time.•There are few reports on the determination of validamycin A in food.•Validamycin A determination in agricultural food matrix.For the first time, a rapid, sensitive and accurate liquid chromatography–atmospheric pressure chemical ionisation–tandem mass spectrometry (LC–APCI–MS/MS) method was developed for determination of validamycin A in agricultural food samples (rice, agaric, almond, cabbage, green onion, carrot, tomato, cucumber and spinach). The validamycin A residue was extracted with methanol–water (9/1, v/v) or methanol by vortex, and a HLB solid-phase extraction cartridge was used for cleaning up the extracts. LC–APCI–MS/MS data acquisition was carried out in multiple reaction monitoring (MRM) mode. A series of matrix-matched calibration solutions ranging from 2.5 to 50 ng mL−1 were used to record calibration curve. The limit of quantification (LOQ) was 10 μg kg−1. The average recoveries, measured at three concentrations levels (10.0, 50.0, 100.0 μg kg−1) were in the range 83.5–109.6%. The proposed method offers the best sensitivity and specificity for the routine analysis of validamycin A in agricultural food samples.

Increasing attention has been focused on the artificial flavorings added in foods, especially those for infants and children. For the first time, a sensitive and efficient analytical method based on gas chromatography–tandem mass spectrometry (GC-MS/MS) was developed for the simultaneous identification and quantification of four flavoring agents (vanillin, methylvanillin, ethylvanillin, and coumarin) in infant formula samples. The flavorings in samples were extracted with methanol/water (v/v, 1:1), cleaned up by solid-phase extraction, and determined by GC-MS/MS in selected reaction monitoring (SRM) mode. Both isotope-labeled internal standards and matrix-matched calibration solutions were used to correct the matrix effects. The limit of quantification (LOQ) was calculated as 10 times the standard deviation, and it was 10.0 μg kg –1 for vanillin, methylvanillin, ethylvanillin, and coumarin. The average recoveries were in the range of 82.8–107.5% with relative standard deviations (RSDs) below 8.9% measured at three concentration levels (10, 50, and 100 μg kg–1). The proposed method is suitable for the sensitive and accurate simultaneous determination of four flavoring agents in infant formula samples and also provided potential use for reference in terms of real analysis of other foods.

A method for simultaneous determination of the 30 organochlorine pesticides (OCP) in milk and milk powder samples has been developed. Prior to the gas chromatography-tandem mass spectrometric analysis, the residual OCP in samples were extracted with n-hexane and acetone mixture (1/1, vol/vol) and cleaned up by gel permeation chromatography and solid phase extraction. Selected reaction monitoring mode was used for gas chromatography-tandem mass spectrometric data acquisition to identify and quantify the OCP. To avoid the matrix effects, matrix-matched calibration solutions ranging from 2 to 50 ng/mL were used to record the calibration curve. Limits of quantification of all OCP were 0.8 μg/kg. With the exception of endrin, limits of quantification are significantly lower than maximum residue limits set by the European Union and China. The average recoveries were in the range of 70.1 to 114.7% at 3 spiked concentration levels (0.8, 2.0, and 10.0 μg/kg) with residual standard deviation lower than 12.9%. The developed method was successfully applied to analyze the OCP in commercial milk products.

A simple, precise, accurate, and validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of dicyandiamide residue in infant formula samples. Following microwave-assisted extraction with 5% formic acid and clean-up on a Sep-Pak AC-2 SPE cartridge, samples were separated on a ZIC-HILIC HPLC column (150 × 2.1 mm i.d., 5-µm film thickness; Merck KGaA, Darmstadt, Germany) with 20 mM ammonium acetate solution-acetonitrile as mobile phase at a flow rate of 0.25 mL/min. A linear calibration curve was obtained in the concentration range from 1.0 to 50 ng/mL. Infant formula samples were fortified with dicyandiamide at 3 levels, producing average recovery yields of 83.6 to 95.7%. The limits of detection and quantification of dicyandiamide were 3 and 10 μg/kg, respectively. Due to its simplicity and accuracy, the straightforward method is particularly suitable for routine dicyandiamide detection.

A simple, precise, accurate, and validated liquid chromatography-quadrupole linear ion trap mass spectrometry method was developed for the determination of vanillin, ethyl vanillin, and coumarin in infant formula samples. Following ultrasonic extraction with methanol/water (1:1, vol/vol), and clean-up on an HLB solid-phase extraction cartridge (Waters Corp., Milford, MA), samples were separated on a Waters XSelect HSS T3 column (150 × 2.1-mm i.d., 5-μm film thickness; Waters Corp.), with 0.1% formic acid solution-acetonitrile as mobile phase at a flow rate of 0.25 mL/min. Quantification of the target was performed by the internal standard approach, using isotopically labeled compounds for each chemical group, to correct matrix effects. Data acquisition was carried out in multiple reaction monitoring transitions mode, monitoring 2 multiple reaction monitoring transitions to ensure an accurate identification of target compounds in the samples. Additional identification and confirmation of target compounds were performed using the enhanced product ion modus of the linear ion trap. The novel liquid chromatography-quadrupole linear ion trap mass spectrometry platform offers the best sensitivity and specificity for characterization and quantitative determination of vanillin, ethyl vanillin, and coumarin in infant formula and fulfills the quality criteria for routine laboratory application.