Yongjiang Wu

Simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in peanuts and their derivative products by ultra-high-performance liquid chromatography-tandem mass spectrometry.

A reliable 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 peanuts and their derivative products was developed. The sample was extracted by 84% of acetonitrile aqueous solution and the extract was purified by a reliable solid phase extraction-based clean-up method. Then, the analytes were separated on Acquity UPLC HSS T3 column (100 mm x 2.1 mm, 1.8 microm particle size), and eluted with a mobile phase consisting of (A) water containing 0.1% formic acid and (B) acetonitrile/methanol (50/50, v/v). The separated compounds were detected with a Waters Micromass Quattro Ultima Pt tandem quadrupole mass spectrometer operating in positive electro-spray ionization using multiple reaction monitoring mode. The established method was extensively validated by determining the linearity (R(2) > or = 0.9990), average recovery (74.7-86.8%) and precision (relative standard deviation < or = 10.9%). It was shown to be a suitable method for simultaneous determination of the six aflatoxins in peanuts and their derivative products. Finally, a total of 73 samples randomly collected from different areas in Zhejiang province were screened for aflatoxins with the proposed method. The results showed that 31 samples of peanut butter, 14 samples of fresh peanut and 5 samples of musty peanut were contaminated with aflatoxins. Meanwhile, this was the first report on aflatoxins M1 and M2, which were found in unprocessed peanuts and their derivative products.

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.

Quantitative analysis combined with chromatographic fingerprint for comprehensive evaluation of Danhong injection using HPLC-DAD

A simple, reliable method for simultaneous determination of the ten components in Danhong injection (DHI) in combination of chromatographic fingerprint analysis was developed by high performance liquid chromatography coupled with diode-array-detector (HPLC-DAD). The separation was performed on an Agilent Zorbax SB-C(18) column with a linear gradient elution of acetonitrile and 0.5% formic acid. The method was validated by linearity, precision, stability and recovery. The developed method was subsequently applied to evaluate 15 batches of DHI and testified to be suitable for its quality control.

Analysis of ochratoxin A and ochratoxin B in traditional Chinese medicines by ultra-high-performance liquid chromatography–tandem mass spectrometry using [13C20]-ochratoxin A as an internal standard

The paper reported a reliable analytical method for simultaneous determination of ochratoxin A (OTA) and ochratoxin B (OTB) in traditional Chinese medicines (TCMs) by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The development of the method and investigations on the matrix influence were described in particular. The matrix effects were thereby minimized by using a reliable internal standard and a simple sample pretreatment. The established method was further validated by determining the linearity (R(2) > or = 0.9990), average recovery (86.3-114.2%), sensitivity (limit of quantitation 0.03-0.19 ng mL(-1)) and precision (relative standard deviation < or = 13.1%). It was shown to be a suitable method for simultaneous determination of OTA and OTB in various TCMs. Finally, a total of 51 TCMs widely used in China were screened for OTA and OTB with the proposed method. The results showed that only 4 samples were contaminated with ochratoxins at low levels, indicating that it was low risk of ochratoxins to consumers who occasionally used TCMs.

Simultaneous determination of 10 mycotoxins in grain by ultra-high-performance liquid chromatography–tandem mass spectrometry using 13C15-deoxynivalenol as internal standard

An ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) method for simultaneous determination of 10 mycotoxins in grain was developed. The selected mycotoxins were: deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, fusarenon X, moniliformin, zearalenone, zearalanone, ochratoxin A and ochratoxin B. The samples were extracted with aqueous acetonitrile (84 : 16, v/v) and purified by reliable laboratory-made mixed cartridges. The analytes were separated on an Acquity UPLC HSS T3 column (100 × 2.1 mm, 1.8 µm) and eluted with a mobile phase of water containing 0.2% aqueous ammonia and acetonitrile/methanol (90 : 10, v/v). All mycotoxins were detected with a Waters Micromass Quattro Ultima Pt tandem quadrupole mass spectrometer operating in negative electrospray ionization using multiple reaction monitoring mode. Accurate determination was achieved by employing commercial 13C15-deoxynivalenol as internal standard, which compensated for target loss and eliminated matrix effects. The established method was further validated by determining the linearity (R 2 > 0.9990), average recovery (75.8–106.5%), sensitivity (limit of quantitation 0.09–8.48 µg kg−1) and precision (relative standard deviation ≤ 6.9%). It was shown to be a suitable method for simultaneous determination of 10 mycotoxins in grain. Finally, a total of 69 corn samples randomly collected from eastern and northern China were analyzed. The results showed that deoxynivalenol was the most frequently detected contaminant, whilst 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, nivalenol, zearalenone, zearalanone, fusarenon X and moniliformin also occurred frequently. Ochratoxin A and ochratoxin B were present only in trace amounts in a small number of samples.

Simultaneous determination of four alkaloids in Lindera aggregata by ultra-high-pressure liquid chromatography-tandem mass spectrometry

A new separation and quantification method using liquid chromatography under ultra-high-pressure in combination with tandem mass spectrometry (MS/MS) was developed for simultaneous determination of four alkaloids in Lindera aggregata. The analysis was performed on an Acquity UPLC BEH C(18) column (50mmx2.1mm, 1.7microm particle size; Waters, Milford, MA, USA) utilizing a gradient elution profile and a mobile phase consisting of (A) water containing 10mM ammonium acetate adjusted to pH 3 with acetic acid and (B) acetonitrile. An electrospray ionization (ESI)-tandem interface in the positive mode was employed prior to mass spectrometric detection. The calibration curve was linear over the range of 17.1-856ng for boldine, 42.4-2652ng for norboldine, 6.1-304ng for reticuline and 0.5-50ng for linderegatine, respectively. The average recoveries ranged from 99.2 to 101.4% with RSDs< or =2.7%. Then, four L. aggregata samples from different batches were analyzed using the established method. The results indicated that ultra-high-pressure liquid chromatography-tandem mass spectrometry provided improved chromatographic parameters resulting in significantly increased sample throughput including lower solvent consumption and lower limits of quantitation (LOQs) for most of target analytes compared to previous method employing conventional high-performance liquid chromatography (HPLC) separation. So, the established method was validated, sensitive and reliable for the determination of four alkaloids in L. aggregata.

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 reliable isotope dilution method for simultaneous determination of fumonisins B1, B2 and B3 in traditional Chinese medicines by ultra-high-performance liquid chromatography-tandem mass spectrometry.

A reliable isotope dilution method for simultaneous determination of fumonisin B1, fumonisin B2 and fumonisin B3 in traditional Chinese medicines by ultra-high-performance LC-MS/MS was developed, and a special focus was placed on the optimization of extraction, cleanup, ultra-high-performance LC separation and MS/MS conditions. Homogenized samples were extracted by 50% acetonitrile aqueous solution and purified with MultiSep 211 Fum columns. A linear gradient mobile phase, consisting of water containing 0.2% formic acid and acetonitrile/methanol (50:50 v/v) and an Acquity UPLC HSS T3 column (100 mm×2.1 mm, 1.8 μm) were employed to obtain the best resolution of the analytes for the positive ESI(+) analysis. The established method was validated by determining the linearity (R(2)≥0.9991), sensitivity (LOQ, 0.08-0.16 ng/mL), recovery (88.2-113.3%) and precision (RSD≤12.3%). Finally, the validated method was successfully applied to the determination of fumonisins in different traditional Chinese medicines. Of 35 samples, 18 were contaminated with fumonisins. The mean levels (incidence) of fumonisin B1, fumonisin B1 and fumonisin B1 in positive samples were 8.55 (94.4%), 4.88 (77.8%) and 0.52 μg/kg (33.3%), respectively. Based on the contaminant situations, a possible association between the contamination levels and the selected herbs was clarified in this study.

A rapid method for simultaneous determination of zearalenone, α-zearalenol, β-zearalenol, zearalanone, α-zearalanol and β-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), β-zearalenol (β-ZOL), zearalanone (ZAN), α-zearalanol (α-ZAL) and β-zearalanol (β-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, β-ZOL, ZAN, α-ZAL and β-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.

Simultaneous determination of bovine α-lactalbumin and β-lactoglobulin in infant formulae by ultra-high-performance liquid chromatography-mass spectrometry.

A reliable ultra-high-performance liquid chromatography-mass spectrometry method for simultaneous determination of bovine alpha-lactalbumin (alpha-La) and beta-lactoglobulin (beta-Lg) was developed. Compared to the previous methods, the developed approach with mass spectrometer operated in selected area monitoring mode offered increased speed and enhanced lower detection limit. A linear gradient mobile phase, consisting of (A) water containing 0.1% trifluoroacetic acid (TFA) and (B) acetonitrile containing 0.1% TFA, and an Acquity UPLC BEH300 C18 column (150mmx2.1mm, 1.7microm) were employed to obtain the best resolution of the target analytes. The accurate quantitation was achieved by employing human alpha-lactalbumin as the internal standard. The established method was extensively validated by determining the linearity (R(2)>or=0.9991), sensitivity (limit of quantitation, 0.15-0.19microgmL(-1)), recovery (94.0-98.7%), precision (relative standard deviation<or=11.1%) and repeatability (relative standard deviation<or=5.7%). It was shown to be a suitable method for simultaneous determination of the major whey proteins in biological samples. Current validated method was successfully applied to the nutrient investigation of infant formulae.