高分辨质谱技术在农药残留检测中的应用

农药残留检测是农产品中有害物质控制的重要组成部分,随着农药残留限量标准体系的发展完善,农药残留检测方法也在不断进步。近年来质谱技术发展迅速,已被广泛应用于农药残留检测领域,高分辨质谱由于具有较高的分辨率和质量精确度,在复杂基质的农药多残留高通量检测中发挥着越来越重要的作用。本文从高分辨质谱与液相色谱、气相色谱及其他分离模式联用等方面出发,简述了近5年来高分辨质谱在农药残留检测中的应用,对目前高分辨质谱在农药残留检测应用中发现的问题进行了讨论,并对其未来发展趋势进行展望。     

Analysis of veterinary drug residues in cheese by ultra‐high‐performance LC coupled to triple quadrupole MS/MS

A simple, reliable, and fast multiresidue method has been developed for the determination of 17 veterinary drugs belonging to several families (macrolides, sulfonamides, and anthelmintics) in cheese at trace levels. Ultra‐high‐performance LC coupled to MS/MS has been used for the analysis of these compounds in less than 9 min. Veterinary drug residues have been extracted from cheese samples using a QuEChERS (quick, easy, cheap, effective, rugged, and safe)‐based extraction procedure without applying any further clean‐up step. Matrix‐matched calibration was used for quantification and recoveries were calculated at three concentration levels (10, 50, and 100 μg/kg). The obtained values ranged from 70 to 110% for the selected compounds except for tylosin and josamycin at 100 μg/kg (111.7 and 112.7%, respectively). Intra‐ and interday precision were also evaluated and RSDs were lower than 25% in all the cases. LOQs ranged from 0.3 μg/kg (for thiabendazole, oxfendazole, mebendazole, josamycin, and fenbendazole) to 10.5 μg/kg (abamectin), whereas decision limit and detection capability ranged from 2.3 (thiabendazole) to 11.3 (abamectin) and 4.2 (thiabendazole) to 14.3 μg/kg (abamectin), respectively. Finally, 13 samples were analyzed and traces of thiabendazole were detected in two different cheeses.     

Development and validation of a high‐resolution LTQ Orbitrap MS method for the quantification of isoflavones in wastewater effluent

Isoflavones and coumestranes are the most important classes of compounds among phytoestrogens; by binding to estrogen receptors, they mimic or modulate the effect on the endogenous receptors. Little information can be found in literature about the presence of isoflavones and coumestrol in the environment, even if it is known that this may have significance, being these substances classified as endocrine disrupting compounds. In this research, we aim to explore the capabilities of the LTQ Orbitrap Discovery hybrid MS in full‐scan acquisition mode, with high resolution, to validate an analytical method for the quantification of nine isoflavones (genistein, genistin, glycitein, daidzein, daidzin, (R,S)‐equol, biochanin A, formononetin and coumestrol) in wastewater samples. The correlation coefficients of calibration curves of the nine analyzed compounds were in a range of 0.996–0.999; recoveries at two different levels of concentration (0.05 and 0.5 µg/l) were in the range 73–98%, and the limits of detection ranged between 0.0014 and 0.017 µg/l, proving that this method is sensitive enough in comparison with other methods available in literature. This method has been applied for the analysis of 20 wastewater treatment plants in County Cork, Ireland. Copyright © 2015 John Wiley & Sons, Ltd.     

Dual‐layer column filtration cleanup and gas chromatography‐tandem mass spectrometry detection for the analysis of 39 pesticide residues in porcine meat

A rapid and effective method was developed for the analysis of 39 pesticide residues in porcine meat with dual‐layer multiplug filtration cleanup and gas chromatography‐tandem mass spectrometry detection. The cleanup process was performed with columns packed with two layers, namely multiwalled carbon nanotubes, C18 and anhydrous magnesium sulfate (MgSO₄) as top layer, while mixture of florisil and MgSO₄ as bottom layer. A single‐layer method was tested in parallel, with columns packed with the same amount of absorbents. Extraction conditions and filtration cleanup process were optimized to obtain satisfied method performance. Method linearity was calculated with coefficients of determination more than 0.995. The limits of quantitation were verified with acceptable accuracy at the lowest spiked concentration of 0.01 mg/kg (except pyrimethanil). The recoveries at three fortified levels (0.01, 0.05, and 0.1 mg/kg) in five replicates were between 74 and 118% (except pyrimethanil) with relative standard deviations range from 1 to 16%. The matrix effects were in the range of 1.01 to 2.84. This new method was applied for the analysis of multipesticide residues in market samples of porcine meat. This study showed the dual‐layer multiplug filtration cleanup demonstrated better performance than that with the single‐layer columns in cleanup of porcine meat.     

Multi‐mycotoxin analysis in complex biological matrices using LC‐ESI/MS: Experimental study using triple stage quadrupole and LTQ‐Orbitrap

In the present study, we report the application of LC‐MS based on two different LC‐MS systems to mycotoxin analysis. The mycotoxins were extracted with an ACN/water/acetic acid mixture and directly injected into a LC‐MS/MS system without any dilution procedure. First, a sensitive and reliable HPLC‐ESI‐MS/MS method using selected reaction monitoring on a triple quadrupole mass spectrometer (TSQ Quantum Ultra AM) has been developed for determining 32 mycotoxins in crude extracts of wheat and maize. This method was operated both in positive and in negative ionization modes in two separate chromatographic runs. The method was validated by studies of spiked recoveries, linearity, matrix effect, intra‐assay precision and sensitivity. Further, we have developed and evaluated a method based on accurate mass measurements of extracted target ions in full scan mode using micro‐LC‐LTQ‐Orbitrap as a tool for fast quantitative analysis. Both instruments exhibited very high sensitivity and repeatability in positive ionization mode. Coupling of micro‐LC to Orbitrap technology was not applicable to the negatively ionizable compounds. The LC triple quadrupole MS method has proved to be stable in quantitation, as it is with respect to the matrix effects of grain samples.     

超高效液相色谱-串联质谱法快速检测蔬菜中248种农药残留

采用超高效液相色谱-串联质谱（UHPLC-MS/MS）技术建立了快速检测蔬菜中248种农药残留的分析方法。蔬菜样品采用乙腈提取,盐析后无需净化,缩短了样品前处理的时间。采用正负离子多反应监测（MRM）模式对蔬菜中248种农药残留进行定性和定量分析。245种农药在各自的线性范围内线性关系良好（r>0.99）。除丁硫克百威、灭蝇胺、苯磺隆和二氯喹啉酸4种农药外,其余244种农药在3个添加水平下的平均回收率范围为63.0%～126.4%,相对标准偏差（RSD）范围为0.5%～26.7%,方法的定量限为0.001～0.030 mg/kg。该方法具有简单、快速、灵敏度高、准确度高等优点,适合蔬菜样品中农药多残留的快速检测分析。     

UPLC-MS/MS检测3种蔬菜中的11种农药

建立了使用超高效液相色谱-串联质谱(UPLC-MS/MS)快速有效测定甘蓝、豇豆以及菠菜三种蔬菜中11种常见农药残留的方法。蔬菜样品经乙腈提取,Cleanert-NH2固相萃取柱净化后,采用ACQUITY UPLC·BEH C18色谱柱分离,以电喷雾电离、多反应监测模式检测。考察了不同配比的甲醇-水组成的流动相对电离效率、分辨率和灵敏度的影响,研究了不同蔬菜样品中的基质效应。通过基质匹配标准曲线进行定量,11种农药在5~100μg·L-1范围内线性良好,线性相关系数r0.99,目标农药的检出限在0.05~0.5μg·kg-1之间,11种农药在0.01 mg·kg-1,0.05 mg·kg-1和0.10 mg·kg-1三个加标水平下的回收率为80%~120%,相对标准偏差为2.7%~16.3%。     

Simultaneous determination of 103 pesticide residues in tea samples by LC‐MS/MS

A simple and sensitive method was developed and validated for the simultaneous determination of 103 pesticide residues in tea by LC‐MS/MS. For the analysis of the pesticide with polarity, thermal lability or low volatility, this LC‐MS/MS method has an advantage over GC. In this work, residual pesticides were extracted from the tea sample with ACN and then purified using Carb‐NH₂ SPE cartridges. Using the multiple reaction monitoring mode, the pesticides were quantified and identified by the most abundant and characteristic fragment ions. The recoveries obtained for each pesticide ranged between 65 and 114% at three spiked concentration levels. The intra‐day precisions were lower than 19.6%. Good linear relationships were observed with the correlation coefficients r² >0.996 for all analytes. The established method was successfully applied to the determination of pesticide residues in real tea samples.     

分散固相萃取净化-超高效液相色谱-串联质谱法同时测定鱼和虾中抗生素及三苯甲烷类兽药残留

建立了分散固相萃取净化-超高效液相色谱-串联质谱法快速测定鱼和虾中3类（磺胺类、喹诺酮类、氯霉素类）18种抗生素及2种三苯甲烷类（孔雀石绿、隐色孔雀石绿）兽药残留。样品经磷酸氢二钾溶液水解分散，乙腈提取，提取液经氯化钠脱水、盐析后取乙腈层，经旋转蒸发仪浓缩至近干，残留物用甲醇定容至1.0 mL，C18和PSA（N-丙基乙二胺）填料分散固相萃取净化，过滤膜后经ZORBAX C18色谱柱（50 mm×2.1 mm，1.8 μm）分离，正、负离子多反应监测模式采集数据，同位素内标法定量。实验结果表明，20种兽药在0.2~300 μg/L范围内具有良好的线性关系，检出限为0.1~0.6 μg/kg，定量限为0.3~1.8 μg/kg，相关系数均大于0.99。在1、5和20倍定量限加标浓度水平下，平均回收率为72.5%~118%，相对标准偏差（RSD）为1.9%~9.8%。该方法具有前处理简单、检测效率高、成本低等优点，适用于鱼和虾中多类兽药残留的同时测定。     

Quantification of human and veterinary antibiotics in water and sediment using SPE/LC/MS/MS

An analytical method was developed and tested for four different groups of veterinary antibiotics in both river water and sediment matrices. Solid phase extraction (SPE) was used to enrich and to clean up the aqueous sample. Also, Mcllvaine and ammonium hydroxide buffer solutions were used to extract the compounds from the sediment matrix. High performance liquid chromatography (HPLC) equipped with tandem mass spectrometry (MS/MS) was used to separate and quantify the samples. The range of recoveries (in percent) for tetracyclines (TCs), sulfonamides (SAs), macrolides (MLs), and ionophore polyethers (IPs) in the water matrix were 102.2–124.8, 76.6–124.3, 89.5–114.7, 82.7–117.5 with 1–13 (%) of relative standard deviation respectively with three different concentrations. For sediment, the percent recovery ranges were 32.8–114.8, 62.4–108.9, 53.4–128.4 and 51.3–105.4 for TCs, SAs, MLs and IPs, respectively. The relative standard deviation ranged from 16 – 27 (%) over three different concentrations. The limit of quantification (LOQ) was determined by two different methods and calculated to be in the range of 0.01–0.04 μg/l and 0.3–2.5 μg/kg for TCs, SAs, and MLs in water and sediment, respectively. For IPs, the LOQ was 0.001–0.003 μg/l in river water and 0.4–3.6 μg/kg for sediment. The sediment concentration measured in an agriculture-influenced river was much higher than in the overlying water matrix, indicating a high degree of sediment partitioning for these compounds.     

Simultaneous analysis by Quadrupole‐Orbitrap mass spectrometry and UHPLC‐MS/MS for the determination of sedative‐hypnotics and sleep inducers in adulterated products

Adulterated products are continuously detected in society and cause problems. In this study, we developed and validated a method for determining synthetic sedative‐hypnotics and sleep inducers, including barbital, benzodiazepam, zolpidem, and first‐generation antihistamines, in adulterated products using Quadrupole‐Orbitrap mass spectrometry and ultrahigh performance liquid chromatography with tandem mass spectrometry. In Quadrupole‐Orbitrap mass spectrometry analysis, target compounds were confirmed using a combination of retention time, mass tolerance, mass accuracy, and fragment ions. For quantification, several validation parameters were employed using ultrahigh performance liquid chromatography with tandem mass spectrometry. The limit of detection and limit of quantitation was 0.05–53 and 0.17–177 ng/mL, respectively. The correlation coefficient for linearity was more than 0.995. The intra‐ and interassay accuracies were 86–110 and 84–111%, respectively. Their precision values were evaluated as within 4.0 (intraday) and 10.7% (interday). Mean recoveries of target compounds in adulterated products ranged from 85 to 116%. The relative standard deviation of stability was less than 10.7% at 4°C for 48 h. The 144 adulterated products obtained over 3 years (2014–2016) from online and in‐person vendors were tested using established methods. After rapidly screening with Quadrupole‐Orbitrap mass spectrometry, the detected samples were quantified using ultrahigh performance liquid chromatography with tandem mass spectrometry. Two of them were adulterated with phenobarbital.     

Structure elucidation of phototransformation products of unapproved analogs of the erectile dysfunction drug sildenafil in artificial freshwater with UPLC‐Q Exactive‐MS

In this study, four unapproved analogues of Sildenafil (SDF) were photodegraded under synthetic sunlight in artificial freshwater. Homosildenafil (H‐SDF), hydroxyhomo‐sildenafil (HH‐SDF), norneosildenafil (NR‐SDF) and thiosildenafil (T‐SDF) were selected because they are frequently detected as adulterants in natural herbal products. Using UPLC‐Orbitrap (Q Exactive)‐MS, six photoproducts common to H‐SDF, HH‐SDF and T‐SDF and nine unique transformation products of different molecular weights were identified based on their high‐resolution (+)ESI product ion spectra. Mass spectral analysis of deuterated H‐SDF, labeled on the N‐ethyl group, allowed to gain mechanistic insight into the fragmentation pathway of the substituted piperazine ring and to support the postulated photoproduct structures. The mass spectral fragmentation confirmed the stepwise destruction of the piperazine ring eventually producing a sulfonic acid derivative (C₁₇H₂₀N₄O₅S: 392.1151 Da). In contrast, the photodegradation of NR‐SDF, which lacks a piperazine ring in its structure, formed only two prominent photoproducts originating from N,N‐dealkylation of the sulfonamide followed by hydrolysis. The current work constitutes the first study on the photodegradation of analogs of erectile dysfunction drugs and the first detection of two transformation products (m/z 449 and 489) in environmental samples. Copyright © 2014 John Wiley & Sons, Ltd.     

超高效液相色谱-同位素稀释高分辨质谱法测定红葡萄酒中的18种农药残留

建立了采用超高效液相色谱-同位素稀释高分辨质谱法同时快速测定红葡萄酒中18种农药残留的方法。样品采用乙腈提取,以N-丙基乙二胺（PSA）和C₁₈作为吸附剂的分散固相萃取法（d-SPE）进行净化,以BEH C₁₈色谱柱进行色谱分离,分别通过高分辨质谱的全扫描/实时二级质谱扫描（full scan/ddms²）和目标选择离子监测（targeted SIM,tSIM）模式进行定性筛查和定量检测。以多菌灵-D₄、毒死蜱-D₁₀、吡虫啉-D₄、甲氧虫酰肼-D₉、嘧霉胺-D₅和戊唑醇-D₆为内标进行内标法定量,有效地降低了样品基质的影响。待测物在0.5~50 μg/L范围内呈良好的线性关系,相关系数（r）大于0.999。18种农药残留的检出限（LOD）为0.5 μg/kg,定量限（LOQ）为1.0 μg/kg。空白红葡萄酒样品在1~40 μg/kg范围内的4个加标水平的平均回收率为85.4%~117.9%,相对标准偏差为0.5%~6.1%。应用该方法对市售的红葡萄酒样品进行检测,共检出多菌灵、吡虫啉、嘧霉胺、戊唑醇和三唑醇5种农药残留,含量分别为2.6~143.0 μg/kg、0.6~0.9 μg/kg、2.1~3.1 μg/kg、0.6~3.0 μg/kg和0.6 μg/kg。该方法适用于红葡萄酒中农药残留的快速筛查和定量检测。     

Metabolite analysis in Curcuma domestica using various GC‐MS and LC‐MS separation and detection techniques

The metabolic profile of polar (methanol) and non‐polar (hexane) extracts of Curcuma domestica, a widely used medicinal plant, was established using various different analytical techniques, including GC‐FID, GC‐MS, HR‐GC‐MS and analytical HPLC‐ESI‐MS/MS by means of LTQ‐Orbitrap technology. The major non‐volatile curcuminoids curcumin, demethoxycurcumin and bisdemethoxycurcumin were identified when their chromatographic and precursor ion masses were compared with those of authentic standard compounds. In this paper we describe for the first time a GC/MS‐based method for metabolic profiling of the hydrophilic extract. We also identified 61 polar metabolites as TMS derivatives. Copyright © 2009 John Wiley & Sons, Ltd.     

高效液相色谱-串联质谱法同时测定蜂王浆中7种高风险农药残留

建立了高效液相色谱-串联质谱（HPLC-MS/MS）同时测定蜂王浆中氟胺氰菊酯、三唑醇、蝇毒磷、吡氟乙草灵、多菌灵、乙基硫菌灵和甲基硫菌灵7种高风险农药残留的分析方法。样品在碱性条件下经乙腈提取,无水硫酸钠脱水后,采用HLB固相萃取小柱富集净化。采用Venusil MP C18色谱柱分离,以0.5 mmol/L乙酸铵水溶液（含0.1%（v/v）甲酸）-甲醇（含0.1%（v/v）甲酸）为流动相,梯度洗脱。在电喷雾离子（ESI）源、正离子模式和多反应监测（MRM）模式下采集数据,内标法定量。结果表明,7种高风险农药在5~100 μg/kg范围内线性关系良好,相关系数（r²）为0.9921~0.9996;方法的检出限和定量限分别为0.5~2.0 μg/kg和1.0~5.0 μg/kg。在高、中、低3个添加水平下7种农药的加标回收率为80.5%~101.3%,相对标准偏差（RSD）为3.6%~9.4%。该法操作简单,灵敏度高,准确可靠,能够满足出口蜂王浆农残限量检测的要求。     

超高效液相色谱-串联质谱法快速测定鱼和虾中多类禁、限用兽药残留

建立了鱼和虾中5类(磺胺类、喹诺酮类、氯霉素类、硝基呋喃类代谢物、三苯甲烷类)28种禁、限用兽药的同时提取净化-超高效液相色谱-串联质谱(UHPLC-MS/MS)快速检测的方法。对样品前处理及色谱条件进行优化,以盐酸水解样品,待硝基呋喃类代谢物与2-硝基苯甲醛衍生化后,5类残留药物经乙腈提取,提取液经氯化钠脱水、盐析,乙腈层经正己烷净化后浓缩至近干,残留物用甲醇定容至1.0 mL,加50 mg C18、30 mg N-丙基乙二胺(PSA)、60 mg氨基键合硅胶填料(NH2)吸附剂分散固相萃取净化,最后经ZORBAX C18色谱柱(50 mm×2.1 mm, 1.8μm)分离,在正、负离子多反应监测模式下采集,同位素内标法定量。所建立的方法确保28种兽药在各自范围内线性关系良好,相关系数(r)>0.99,方法的检出限和定量限分别为0.1～0.8μg/kg和0.3～2.7μg/kg;在1、5、20倍定量限添加水平下的平均回收率为70.0%～120%,相对标准偏差为0.9%～10.0%。方法简便、快速、准确、灵敏,适用于鱼和虾中多类禁、限用药物的快速测定。     

固相萃取-高效液相色谱-串联质谱联用测定竹笋中残留的7种杀虫剂农药

建立了高效液相色谱-串联质谱(HPLC-MS/MS)同时测定竹笋中丁烯氟虫腈、毒死蜱、氯虫苯甲酰胺、氟虫腈、吡虫啉、茚虫威和辛硫磷7种农药残留的分析方法。样品用乙腈提取后,经PSA固相萃取小柱净化,采用Atlantis T3色谱柱分离,以0.1%甲酸水溶液(含5 mmol/L乙酸铵)和乙腈为流动相,梯度洗脱分离,在电喷雾离子源正、负离子模式下采用质谱多反应监测(MRM)模式检测。结果表明,7种农药在10～100 μg/L范围内具有良好的线性关系(相关系数r为0.9900～0.9994); 4、8、32 μg/kg添加水平下的平均回收率为76.0%～102.6%;相对标准偏差为3.2%～11.0%;7种农药的检出限为0.02～0.5 μg/kg,定量限为0.08～1.5 μg/kg。该方法准确度、灵敏度高,简单、快速,可满足竹笋中7种杀虫剂残留同时检测的要求。     

Development and validation of a solid‐phase extraction method coupled with LC–MS/MS for the simultaneous determination of 16 antibiotic residues in duck meat

The present study was carried out to determine 16 antibiotics belonging to seven different groups (tetracyclines, sulfonamides, penicillins, fluoroquinolones, macrolides, lincosamides and trimethoprims) in duck meat. A solid‐phase extraction method based on Oasis HLB cartridges coupled with liquid chromatography–electrospray ionization tandem mass spectrometry was developed. Solutions of 0.1 m ethylenediaminetetraacetic acid disodium salt and 2% trifluoroacetic acid were used for the preliminary extraction of the target antibiotics from duck meat and n‐hexane was used for purification prior to solid‐phase extraction. Mobile phases composed of 0.1% trifluoroacetic acid in distilled water (solvent A) and 0.1% trifluoroacetic acid in methanol (solvent B), combined with a reversed‐phase C₁₈ analytical column, provided the optimal separation and signal intensity. The linearity of the method was assessed using six concentrations (5, 10, 20, 30, 40, and 50 μg/kg), and the recoveries, which were calculated at three spiking concentrations (5, 10 and 20 μg/kg), were in the range 69.8–103.3% with relative standard deviations (RSDs) ≤ 6.9% for the 16 tested antibiotics. Matrix effects ranging from ?47.2 to ?13.5% were observed for all the analytes, and the limits of quantitation (LOQ), which ranged from 4.93 to 26.21 μg/kg, were much lower than the maximum residue limits (MRLs) set by various regulatory authorities. Ten samples from a market were tested, and none of the target analytes were detected. Thus, a simple and versatile protocol has been developed to detect and quantify 16 antibiotics in duck meat samples.     

液相色谱-四极杆/静电场轨道阱高分辨质谱快速分析动物源性食品中多肽类药物残留

建立了液相色谱-四极杆/静电场轨道阱高分辨质谱(Q/Exactive)分析鸡肉、鸡肝、鸡肾、猪肉、猪肝、猪肾、牛奶和鸡蛋中粘杆菌素A、粘杆菌素B、多粘菌素B、杆菌肽A和维吉尼霉素M的方法。动物源性食品采用1%(体积分数)乙酸乙腈-水(体积比为8∶2)超声提取,提取液直接经C18液相色谱柱分离。在电喷雾正离子模式下,四极杆质谱在m/z 1.2隔离窗口下过滤一级带电离子,高分辨静电场轨道阱质谱在35 000分辨率下进行目标物子离子全扫描(targeted-MS2)。根据5种多肽类药物的高分辨分子离子峰、同位素分布、特征子离子信息建立数据库,采用Trace Finder 3.0软件实现定性检索。为解决多肽类药物残留测定结果重复性差的难题,系统地评价了5种多肽类药物的关键操作技术条件,发现导致该类药物降解的主要因素包括:提取时间、玻璃器皿、存放时间。该方法测定5种多肽类药物时,测定结果的质量精度均小于5×10-6,维吉尼霉素M的定量限(LOQ)为0.5μg/kg,另外4种多肽类药物的LOQ均为10μg/kg。在0.25~500μg/kg范围内,5种多肽类药物的峰面积与质量浓度呈良好的线性关系,相关系数R2≥0.993 1,方法回收率为67.4%~108.9%,相对标准偏差为4.5%~17.2%。该方法操作简单,测定结果准确,可用于动物源性食品中多肽类药物残留的高通量测定。