Rapid screening and quantification of multi-class multi-residue veterinary drugs in royal jelly by ultra performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

A simple and rapid multi-class multi-residue analytical method was developed for the screening and quantification of veterinary drugs in royal jelly by ultra performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). A total of 90 veterinary drugs investigated belonged to more than 14 families such as lincomycins, macrolides, sulfonamides, quinolones, tetracyclines, β-agonists, β-lactams, sedatives, β-receptor antagonists, sex hormones, glucocorticoids, nitroimidazoles, benzimidazoles, nitrofurans, and the others. A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure was used for the sample preparation without solid-phase extraction step. The linearity, sensitivity, accuracy, repeatability, and reproducibility of the method were fully validated. The response of the detector was linear for each target compounds in wide concentration range (at least, two orders of magnitude) with correlation coefficient (R²) of 0.9921–0.9999. The range of the limit of quantification for these compounds in the royal jelly ranged from 0.21 to 20 μg/kg. The repeatability and reproducibility were in the range of 3.01–11.6% and 5.97–14.9%, respectively. The average recoveries ranged from 70.21 to 120.1% with relative standard deviation of 1.77–9.90% at three concentration levels. For the screening method, the data of the precursor and product ions of the target analytes were simultaneously acquired under the All Ions MS/MS mode in a single run. A homemade database including the elemental composition, accurate masses, retention time, isotopic pattern data of the target ions the characteristic in-source fragment ions was utilized for the confirmation and identification of the target compounds. The applicability of the screening method was verified by applying to real royal jelly samples, and certain veterinary drugs were detected in some cases.     

SPME-GC-MS联用技术分析酸水解玉米蛋白粉中的挥发性物质

采用固相微萃取-气相色谱-质谱联用技术对酸水解玉米蛋白粉中的挥发性物质进行分析,并优化固相微萃取条件。结果表明,最优固相微萃取条件为：65 μm聚二甲基硅氧烷/二乙基苯萃取头、2.0 g酸水解玉米蛋白粉、5 mL纯水、2.0 g氯化钠置于萃取瓶中,萃取温度60 ℃、萃取时间30 min。采用气相色谱-质谱联用仪对样品中挥发性物质进行鉴定,共分离出50 种化合物,其中醛类、芳香族类、含硫类、有机酸类、吡嗪类、呋喃类、吡咯类对风味贡献较大。     

水产品中氯霉素检测条件的优化

目的建立液相色谱串联质谱法测定加工水产品中的氯霉素,并对提取溶剂、净化条件、流动相进行了优化。方法样品采用乙酸乙酯提取,HLB固相萃取柱净化,C_(18)色谱柱分离,ESI源负离子模式对氯霉素进行检测。结果氯霉素在0.1~10μg/kg范围内线性关系良好,相关系数为0.999,在基质样品中添加0.1、0.2和10.0μg/kg 3个水平药物,其回收率在95.0%~103.2%之间,相对标准偏差3.72%~6.85%,方法检测限为0.1μg/kg.结论该方法可靠、稳定,可满足加工水产品中氯霉素残留检测与确证需要。     

Research on degradation of penicillins in milk by β-lactamase using ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry

The degradation of penicillin G, penicillin V, and ampicillin in milk in the presence of β-lactamase was investigated by ultra-performance liquid chromatography coupled with electrospray ionization-time-of-flight mass spectrometry. Degradation products of the 3 penicillins in milk were identified based on the fact that the metabolites or degradation products contain a substructure of penicillin, and their degradation pathways in acidic milk in presence of β-lactamase were developed. The influence of factors on the degradation was investigated, including β-lactamase dosage, temperature, time, and acidity. The ratio of the 2 degradation products (penicilloic acid and penilloic acid) is different at different temperatures and pH. Penicilloic acid was the dominant species obtained at pH 6 under 40°C, but, being unstable, it could not be used as a standard for accurate analysis of penicilloic acid, and also could not be used as target for detection of penicillins in milk. Penilloic acid was the dominant species obtained at pH 2 above 40°C; it was stable and could be used as a standard for quantitative analysis and as target for detecting whether penicillins were used in milk.     

熏肠中苯并(α)芘含量的测定

建立固相萃取-高效液相色谱法测定熏肠中苯并(α)芘的检测方法。样品经Cleanert BaP-3固相萃取柱净化、浓缩,C_(18)色谱柱进行分离。结果表明:苯并(α)芘在线性范围0.5~10 ng/mL内,相关系数大于0.99,最低检出限为0.06□g/kg,相对标准偏差小于5%,回收率97.8%~107.0%。本方法快速简便、重现性好,可以用于熏肠中苯并(α)芘含量的测定。     

气相色谱-质谱法检测干辣椒中常用有机磷和拟除虫菊酯类农药的残留

目的建立凝胶色谱技术(GPC)净化和气相色谱质谱法同时测定干辣椒中常用有机磷和拟除虫菊酯类农药的测定方法。方法样品采用乙腈-水提取,经凝胶色谱仪净化去除大分子色素及杂质,再经过石墨化炭黑-氨基SPE柱净化,以气相色谱-质谱联用仪(EI源)检测,内标法定量。结果在添加水平为0.05~0.5 mg/kg下的平均回收率为71.6%~116.4%,相对标准偏差在2.3%~10.8%之间,样品最低检出限为0.01~0.05 mg/kg。结论此方法净化效果显著,测定结果准确,实验周期短,基本实现全自动化,节省大量时间与试剂,适用于大批量辣椒的农药残留检测。     

50%烟嘧磺隆·甲基磺草酮·氯氟吡氧乙酸异辛酯水分散粒剂防除夏玉米田杂草防效与安全性

[目的]为明确50%烟嘧磺隆·甲基磺草酮·氯氟吡氧乙酸异辛酯水分散粒剂对夏玉米田杂草的防效及对玉米的安全性。[方法]采用茎叶喷雾施药,定期调查的方法进行田间药效试验。[结果]50%烟嘧磺隆·甲基磺草酮·氯氟吡氧乙酸异辛酯水分散粒剂的推荐用量为97.5~195 g a.i./hm2。施药28 d后对杂草总体防效可高达98.17%。[结论]50%烟嘧磺隆·甲基磺草酮·氯氟吡氧乙酸异辛酯水分散粒剂能够有效防除玉米田杂草并对玉米具有较好的安全性。     

水果中菊酯类农药残留的快速检测分析

目的建立水果中菊酯类农药残留的气相色谱法快速检测方法,为今后检验工作提供可靠参考依据。方法所选取的水果样品经粉碎、乙腈提取、CleanertPC/NH_2 SPE柱净化、氮吹仪浓缩后,进入GC分析,外标法定量。结果 4种菊酯类农药在0.008~0.4μg/mL浓度范围内具有良好的线性响应,分离效果好,相关系数在0.99903到0.99993之间,添加量为0.002 mg/kg时,加标回收率在91.43%~100.94%之间,相对标准偏差在5.45%~8.20%之间,检出低限为0.002 mg/kg。结论该方法简便、快速、具有较高的精密度和准确度。     

酸水解玉米蛋白调味粉中非挥发性风味物质的同时测定

采用衍生化与气相色谱-质谱联用技术分析酸水解玉米蛋白调味粉甲醇提取液中的非挥发性风味物质,并优化衍生化条件。最佳衍生化条件为盐酸羟胺-无水吡啶质量浓度3.0 μg/mL、甲醇提取液用量250 μL,衍生温度70 ℃、衍生时间20 min。采用气相色谱-质谱联用对不同样品中的非挥发性风味物质进行分析,共分离鉴定出62 种物质,用山梨醇为内标物对化合物进行了定量,其中氨基酸、酸类、糖类、醇类和内酯类物质对风味贡献较大。     

生活用水中六六六和滴滴涕的残留分析

目的利用气相色谱法测定自来水、桶装水、纯水、蒸馏水中的六六六和滴滴涕含量,研究六六六和滴滴涕对不同生活用水污染情况。方法采用液液萃取方法,用石油醚提取水中六六六和滴滴涕,氮吹仪浓缩后用气相色谱仪ECD检测器检测,外标法定量。结果不同生活用水中六六六和滴滴涕均有检出,其中β-BHC、o,p′-DDT检出率为100%,α-BHC检出率为75%,纯水中和桶装水中含量较低。结论六六六、滴滴涕由于其化学性质稳定及高残留性所引起的远期危害不容忽视。