A novel single step solid-phase extraction combined with bromine derivatization method for rapid determination of acrylamide in coffee and its products by stable isotope dilution ultra-performance liquid chromatography tandem triple quadrupole electrospray ionization mass spectrometry.

This work aimed to establish a novel determination method for acrylamide in coffee and its products by ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). Acrylamide in samples were prepared by a single-step solid-phase extraction clean-up using mixed mode sorbents. The bromine derivatization efficiency of acrylamide and its internal standard were improved at an acidic condition. After derivation, the retention capability of acrylamide and its resistance to interference were significantly improved. The limit of detection (LOD) and the limit of quantification (LOQ) were 1.2 and 4 µg/kg for roasted and instant coffees, while they were 0.24 and 0.8 µg/kg for ready-to-drink coffees. The average recoveries for acrylamide ranged from 99.3 to 102.2% in coffee and its products. All the results showed that the developed method was simple, quick, specific and suitable for screening and determination of acrylamide in batch samples of coffee and its products.

Bivariate Correlation Analysis of the Chemometric Profiles of Chinese Wild Salvia miltiorrhiza Based on UPLC-Qqq-MS and Antioxidant Activities.

To better understand the mechanisms underlying the pharmacological actions of Salvia miltiorrhiza, correlation between the chemical profiles and in vitro antioxidant activities in 50 batches of wild S. miltiorrhiza samples was analyzed. Our ultra-performance liquid chromatography-tandem mass spectrometry analysis detected twelve phenolic acids and five tanshinones and obtained various chemical profiles from different origins. In a principal component analysis (PCA) and cluster analysis, the tanshinones cryptotanshinone, tanshinone IIA and dihydrotanshinone I exhibited higher weights in PC1, whereas the phenolic acids danshensu, salvianolic acids A and B and lithospermic acid were highly loaded in PC2. All components could be optimized as markers of different locations and might be suitable for S. miltiorrhiza quality analyses. Additionally, the DPPH and ABTS assays used to comprehensively evaluate antioxidant activities indicated large variations, with mean DPPH and ABTS scavenging potencies of 32.24 and 23.39 µg/mL, respectively, among S. miltiorrhiza extract solutions. Notably, samples that exceeded the mean IC50 values had higher phenolic acid contents. A correlation analysis indicated a strong correlation between the antioxidant activities and phenolic acid contents. Caffeic acid, danshensu, rosmarinic acid, lithospermic acid and salvianolic acid B were major contributors to antioxidant activity. In conclusion, phenolic compounds were the predominant antioxidant components in the investigated plant species. These plants may be sources of potent natural antioxidants and beneficial chemopreventive agents.

Multianalysis of 35 mycotoxins in traditional Chinese medicines by ultra-high-performance liquid chromatography-tandem mass spectrometry coupled with accelerated solvent extraction.

A generic procedure, which involved accelerated solvent extraction and homemade cleanup cartridges, has been developed for the extraction and purification of 35 mycotoxins in various traditional Chinese medicine (TCM) matrixes, i.e., rhizomes and roots, seeds, flowers, and grasses and leaves, for subsequent analysis by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). All target analytes could be simultaneously quantitated in less than 17 min per run, showing narrow symmetrical peaks. The developed method was also successfully applied in routine monitoring programs, which implied a significant reduction of both effort and time, to investigate the contamination of TCMs. Among 60 commercial TCMs analyzed, 50 were positive. The achieved data underpin the practical application of the UHPLC-MS/MS method as a valuable tool for the trace analysis of multiple mycotoxins in TCMs.

A rapid method for simultaneous determination of zearalenone, α-zearalenol, ß-zearalenol, zearalanone, α-zearalanol and ß-zearalanol in traditional Chinese medicines by ultra-high-performance liquid chromatography-tandem mass spectrometry.

A rapid and reliable ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of zearalenone (ZEN), α-zearalenol (α-ZOL), ß-zearalenol (ß-ZOL), zearalanone (ZAN), α-zearalanol (α-ZAL) and ß-zearalanol (ß-ZAL) in traditional Chinese medicines (TCMs) was developed. The development of the method and investigations of the matrix influence were described in particular. After evaluation of the matrix effects of different TCMs, i.e., rhizomes and roots, seeds, flowers, grasses and leaves, by the post-extraction spiked method, a reliable sample clean-up method based on home-made clean-up cartridges, a suitable internal standard and the matrix calibration were combined using to minimize the matrix effects to ensure the accuracy of the method. The established method was further validated by determining the linearity (R(2)≥0.9990), sensitivity (limit of quantitation 0.11-0.99 ng mL(-1)), average recovery (86.6-113.5%) and precision (relative standard deviation ≤13.5%). It was shown to be a suitable method for simultaneous determination of ZEN, α-ZOL, ß-ZOL, ZAN, α-ZAL and ß-ZAL in different TCMs. Finally, the established method was successfully applied to the determination of the six mycotoxins in various TCMs and the results were presented to provide relevant insights to researchers in TCM analysis.

Multi-residue analysis of pesticides in tea by online SEC-GC/MS.

A multi-residue method for the analysis of pesticides in tea was developed by online size exclusion chromatography (SEC)-GC/MS with full scan mode. The sample was fortified with chlorpyrifos-d(10) isotope internal standard and extracted by acetonitrile. After purification by primary secondary amine sorbent and solvent exchange by SEC mobile phase, the sample was detected by online SEC-GC/MS. The purification result of the online system was evaluated by comparing the correlation between Chinese cabbage and tea matrix. The factors for method optimization included sample preparation, matrix effects and the instrument parameters of each online component. Scatter plot was introduced in this study to directly illustrate the results of the condition optimization and matrix effects in the online system. For most of the pesticides, the average recoveries ranged from 70 to 130% and the RSD were below 15%. The feasibility of the application of full scan mode in multi-residue determination of trace amounts of pesticides (LODs below 0.01 mg/kg) in a complex matrix was discussed.

An ultra-high-performance liquid chromatography-tandem mass spectrometry method for simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in traditional Chinese medicines.

An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in traditional Chinese medicines (TCMs) was developed. The approach was characterized in details and a special focus was placed on the recovery rates of isolation procedure in different TCM matrices, i.e. rhizomes and roots, seeds, flowers, grasses and leaves. For this purpose, [(13)C(17)]-aflatoxinB1 was employed as the internal standard and a reliable solid phase extraction-based clean-up method was developed. The observed recovery rates of the six aflatoxins ranged from 85.6% to 117.6% in different matrices. Then, the established method was successfully applied to the determination of the six aflatoxins in various TCMs. For 30 commercial samples analyzed, 16 were contaminated with aflatoxins. The mean levels (incidence) of aflatoxins B1, B2, G1 and G2 in positive samples were 1.40 (68.8%), 1.27 (50.0%), 0.50 (43.8%) and 0.94 (43.8%) microg kg(-1), respectively. Interestingly, aflatoxin M1 was detected in two samples with the maximal content of 0.70 microg kg(-1). No sample was contaminated with aflatoxin M2. Meanwhile, a possible association between the contamination levels and the selected herbs was clarified in the present study.

Simultaneous determination of four water-soluble vitamins in fortified infant foods by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry.

A novel ultra-performance liquid chromatography electrospray ionization tandem triple quadrupole mass spectrometry method for the simultaneous determination of four water-soluble vitamins, including vitamin B5 (VB5), vitamin B8 (VB8), vitamin B9 (VB9), and vitamin B12 (VB12) in fortified infant foods is developed and validated. A reverse phase UPLC separation system consisting of a Waters ACQUITY UPLC BEH C-18 column (2.1 mm x 100 mm i.d., 1.7 microm) and a binary gradient acetonitrile-water mobile phase is applied for the separation of the four water-soluble vitamins. Formic acid is spiked into the mobile phase to enhance the ionization efficiency. Tandem MS-MS analysis is performed in multi-reaction monitoring mode (MRM). Product-ion traces at m/z 220.1 --> 89.9 for VB5, 245.1 --> 227.1 for VB8, 442.3 --> 295.2 for VB9, and 678.9 --> 147.0 for VB12 are used for quantitation of the corresponding vitamins, and traces at m/z 455.5 --> 308.0 are used for methotrexate (internal standard). Limits of quantitation (LOQs) are 0.016, 0.090, 0.020, and 0.019 microg/L for VB5, VB8, VB9, and VB12, respectively. Intra- and inter-day precisions for the determination of the four vitamins are better than 6.84% and 12.26% in relative standard deviations, and recoveries for the four vitamins are in the range of 86.0~101.5%. The developed approach is applied for the determination of the trace amounts of the vitamins in fortified milk powers and fortified rice powers.