Abstract：
Chromatography combined with mass spectrometry is the most commonly used detection technology, and it offers the advantages of high sensitivity and high selectivity. The quick, easy, inexpensive, effective, rugged, and safe (QuEChERS) method is low-cost, effective, and time efficient. The application of the QuEChERS has now been extended to the analysis of contaminants in food samples. The aim of the study was to identify different concentration levels of multiple harmful drug residues in bean sprouts. In this study, QuEChERS coupled with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the simultaneous determination of 40 plant growth regulators, fungicides, insecticides, and antibiotics in bean sprouts. In the HPLC-MS/MS experiment, gibberellic acid, 4-fluorophenoxyacetic acid, chloramphenicol, N6-(δ2-isopentenyl)-adenine, 6-benzylaminopurine, 4-chlorophenoxyacetic acid, and 2,4-dichlorophenoxyacetic acid (2,4-D) were analyzed by MS/MS with negative electrospray ionization (ESI-). The other 33 target analytes (chlormequat, ronidazole, metronidazole, pymetrozine, dimetridazole, methomyl, carbendazim, enoxacin, levofloxacin, pefloxacin mesylate, norfloxacin, ciprofloxacin, enrofloxacin, thiabendazole, lomefloxacin, chlorpyrifos, sarafloxacin, imidacloprid, etc.) were analyzed by MS/MS with positive electrospray ionization (ESI+). Sensitive MS conditions were realized by optimizing the instrumental parameters such as the desolvent temperature, collision energy, spraying needle position, precursor ions, and product ions. Then, the optimal pretreatment method was determined by comparing the recovery rates of the 40 drugs obtained with different extraction solvents (methanol, acetonitrile, acetonitrile containing 0.1% ammonia, acetonitrile with 1% acetic acid), different extraction methods (ultrasonic extraction, shaking extraction), and purification with primary secondary amine (PSA) and C18. In this study, the bean sprouts samples were extracted twice by 10 mL acetonitrile with 1% acetic acid, and extracted under ultrasonic conditions. Then, the extracting solution was only cleaned with 100 mg C18. The chromatographic separation of the 40 compounds was accomplished on a Waters ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) with gradient elution. Methanol and 0.01% formic acid aqueous solution were used as the mobile phases. The 40 compounds were analyzed in the multiple reaction monitoring (MRM) mode. The matrix matching external standard method was used for quantitative determination. The results showed that the 40 compounds could be analyzed within 15 min. Under the optimized conditions, the calibration curves showed good linearities for the 40 compounds, and the coefficients of determination (r2) were greater than 0.99 in the range of 2-200 μg/L. The limits of detection (LODs) and limits of quantification (LOQs) were in the range of 0.1-3 μg/kg and 0.3-9 μg/kg, respectively. Using negative bean sprouts as the substrates, the recovery tests were carried out at three spiked levels of 5, 10, and 50 μg/kg. The average recoveries of the 40 drugs were 78.5% to 115.3%, and the corresponding relative standard deviations (RSDs) were 1.3% to 9.7% (n=6). This method was successfully applied to the analysis of the 40 drug residues in 21 batches of local bean sprouts in Handan city. The results revealed the presence of extensive drug residues in the bean sprouts. The 26 batches were detected to varying degrees, among which 4-chlorophenoxyacetic acid, carbendazim, 6-benzyladenine, 2,4-D, enrofloxacin, and metronidazole were detected at high rates. The detection rates of 4-chlorophenoxyacetic acid, 6-benzyladenine, carbendazim, 2,4-D, gibberellic acid, and enrofloxacin were 28.6%, 19.0%, 9.5%, 9.5%, 4.8%, and 4.8%, respectively. The contents ranged from 37.5-352.4, 32.4-273.1, 28.8-38.7, 316.1-20.2, 19.9 and 13.6 μg/kg, respectively. Given its advantages of simplicity, rapidness, and high sensitivity, the developed method can be used for the rapid and accurate determination of trace levels of the 40 drug residues in large quantities of bean sprouts.
摘要：
色谱与质谱联用是目前最常用的检测技术,它具有高灵敏度和高选择性的优点。快速，easy,便宜,有效,崎岖,安全(QuEChERS)方法成本低，有效,和时间效率。QuEChERS的应用现已扩展到食品样品中污染物的分析。该研究的目的是鉴定豆芽中不同浓度水平的多种有害药物残留。在这项研究中,建立了同时测定40种植物生长调节剂的高效液相色谱-串联质谱(HPLC-MS/MS),杀菌剂，杀虫剂,和豆芽中的抗生素。在HPLC-MS/MS实验中,赤霉素,4-氟苯氧基乙酸,氯霉素,N6-(δ2-异戊烯基)-腺嘌呤，6-苄基氨基嘌呤,4-氯苯氧基乙酸,和2,4-二氯苯氧基乙酸(2,4-D)通过负电喷雾电离(ESI-)的MS/MS分析。其他33种目标分析物(chlormequat，ronidazole,甲硝唑,吡虫啉,dimetridazole,灭多威,多菌灵,依诺沙星,左氧氟沙星,甲磺酸培氟沙星,诺氟沙星,环丙沙星,恩诺沙星,噻菌灵,洛美沙星,毒死蜱,沙拉沙星,吡虫啉,等。)通过具有正电喷雾电离(ESI+)的MS/MS进行分析。敏感的MS条件是通过优化仪器参数，如脱溶剂温度，碰撞能量,喷针位置,前体离子，和产品离子。然后，通过比较不同提取溶剂（甲醇，乙腈,含0.1%氨的乙腈,含1%乙酸的乙腈)，不同的提取方法(超声波提取，摇动提取)，并用伯仲胺(PSA)和C18纯化。在这项研究中,豆芽样品用10毫升乙腈和1%乙酸提取两次，并在超声波条件下提取。然后，萃取溶液只用100毫克C18清洗。40种化合物的色谱分离是在WatersACQUITYUPLCBEHC18色谱柱（100mm×2.1mm，1.7μm),梯度洗脱。使用甲醇和0.01%甲酸水溶液作为流动相。在多反应监测(MRM)模式下分析40种化合物。采用基质匹配外标法进行定量测定。结果表明,40个化合物在15min内就能被分析。在优化条件下,校准曲线显示40种化合物的良好线性，在2-200μg/L的范围内，测定系数（r2）大于0.99。检出限（LODs）和定量限（LOQs）在0.1-3μg/kg和0.3-9μg/kg范围内，分别。以阴性豆芽为基质，在5、10和50μg/kg的三个加标水平下进行了回收率测试。40种药物的平均回收率为78.5％至115.3％，相应的相对标准偏差（RSD）为1.3％至9.7％（n=6）。该方法成功应用于邯郸市21批次地方豆芽中40种药物残留的分析。结果表明，豆芽中存在大量药物残留。26批次均有不同程度的检出,其中4-氯苯氧基乙酸，多菌灵,6-苄基腺嘌呤，2,4-D,恩诺沙星,甲硝唑的检出率很高。4-氯苯氧基乙酸的检出率,6-苄基腺嘌呤，多菌灵,2,4-D,赤霉素,恩诺沙星占28.6%,19.0%,9.5%,9.5%,4.8%，和4.8%，分别。含量范围为37.5-352.4，32.4-273.1，28.8-38.7，316.1-20.2，19.9和13.6μg/kg，分别。鉴于其简单的优点，快速，灵敏度高,该方法可快速、准确地测定大量豆芽中40种药物的痕量残留。
