Plant protein beverage adulteration occurs frequently, which may cause health problems for consumers due to the hidden allergens. Hence, a novel method was developed for authentication by UPLC-MS/MS. Almond, peanut, walnut and soybean were hydrolyzed, followed by separation by NanoLC-Triple TOF MS. The obtained fingerprints were identified by ProteinPilot^TM combined with Uniprot, and 16 signature peptides were selected. Afterwards, plant protein beverages treated by trypsin hydrolysis were analyzed with UPLC-MS/MS. This method showed a good linear relationship with R² > 0.99403. The LOQs were 0.015, 0.01, 0.5 and 0.05 g/L for almond, peanut, walnut and soybean, respectively. Mean recoveries ranged from 84.77% to 110.44% with RSDs < 15%. The developed method was successfully applied to the adulteration detection of 31 plant protein beverages to reveal adulteration and false labeling. Conclusively, this method could provide technical support for authentication of plant protein beverages to protect the rights and health of consumers.

The aim of this work was to develop a liquid chromatography-tandem mass spectrometry method for the determination of milk allergen and egg allergen in food products. Signature peptides GGLEPINFQTAADQAR, VGINYWLAHK, VLVLDTDYK, FFVAPFPEVFGK, and NAVPITPTLNR were confirmed and synthesized as the quantitative peptide of ovalbumin, α-lactalbumin, β-lactoglobulin, α_S1-casein and α_S2-casein, the relative isotope-labeled internal standards were used in the quantitative analysis. Linear range was in the range of 0.5–5000.0 nmol/L for egg and milk allergen in bread, cake, cookie, rice crust and wheat flour samples with free from egg and milk, the limits of detection of milk allergens and egg allergen were in the range between 0.94 mg/100 g and 56.71 mg/100 g, limits of quantification of milk allergens and egg allergen were in the range between 2.36 mg/100 g and 141.78 mg/100 g. The recoveries ranged from 76.7% to 122.8%, the relative standard deviations were in the range of 1.60%–15.60%. The developed method has been successfully used for the detection of egg and milk allergen in various food samples.

In this experiment, a liquid chromatography tandem mass spectrometry method was built to determine 15 pesticide residues in Chinese cabbage and cucumber samples based on online turbulent flow chromatography purification. After modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) extraction, extracts were directly injected to the TLX (TurboFlow Liquid Xcalibur) system and brought to TurboFlow^TM columns for on-line purification and then transferred to analytical column for further separation and analysis. TurboFlow^TM columns types, transfer flow rate, and transfer time were optimized. Limits of detection and limits of quantification of the method obtained for 15 pesticide residues were ranged between 0.2–1.0 μg/kg and 0.5–2.0 μg/kg in Chinese cabbage and cucumber samples. Recoveries of pesticide residues were in range of 75.3%–103.7%. Matrix effects for 15 pesticides were in range of 5.6%–106.6%. The developed method has been successfully used for the determination of 15 pesticide residues in real samples.

The aim of this work was to develop an automated on-line solid phase extraction (SPE) with liquid chromatography-tandem mass spectrometry method for the detection of fifteen sulfonamides in pork and fish samples. Samples were extracted with 0.2% formic acid acetonitrile solution, purified by on-line SPE device with HLB column, then separated by XBridge C₁₈ column, using 0.1% formic acid solution and acetonitrile as the mobile phase. Mass spectrometric data was acquired under multiple reaction monitoring (MRM) mode using positive ionization electrospray. Internal standard method was used in the quantification, good linear relationship was got in range of 0.1–100 ng/mL and correlation coefficient was higher than 0.9990. The limits of detection were in the range of 0.125–2.00 μg/kg and the limits of quantitation were in the range of 0.250–5.00 μg/kg. Recoveries of the method were in range of 78.3%–99.3%, relative standard deviation were lower than 10%. The method was simple, sensitivity, and could be used for routine supervision and analysis of fifteen sulfonamides in pork and fish.