Determination of nitrofurazone in livestock products and seafoods by liquid chromatography-tandem mass spectrometry

A sensitive and selective method using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the determination of nitrofurazone (NFZ) in swine muscle, swine liver, chicken muscle, chicken liver, egg, eel, yellowtail and shrimp has been developed. The drug was extracted with 0.2% metaphosphoric acid-methanol (6 : 4), and the extracts were cleaned up on an Oasis HLB cartridge (200 mg). The extracts were analyzed by LC-MS/MS using electrospray ionizationin the negative ion mode. The LC separation was performed on a Hypersil Gold C18 column (15 cmx2.1 mm i.d.) with a gradient system of 0.01% formic acid-acetonitrile as the mobile phase at a flow rate of 0.2 mL/min. The quantitative and confirmatory determination of NFZ was performed by selected reaction monitoring (SRM). The calibration graph for NFZ was rectilinear from 0.2 to 100 ng/mL with SRM. The recoveries of NFZ from samples fortified at 1 and 10 ng/g were 79.6-106.8%, and quantification limit was 0.2 ng/g for the drug. This is well below the detection limit (1 ng/g) set by the Japanese Food Sanitation Law.     

超高效液相色谱-串联质谱法测定鸡组织和 牛组织中的甲苄喹啉和癸氧喹酯

目的 建立超高效液相色谱-串联质谱检测鸡组织和牛组织中甲苄喹啉和癸氧喹酯残留的检测方法。方法 样品采用乙腈提取,亲水-亲脂平衡介质固相萃取柱Hydrophile-Lipophile Balance（HLB） 净化,超高效液相色谱-串联质谱仪检测,外标法定量。结果 甲苄喹啉和癸氧喹酯在0.005~0.250 mg/ kg 范围内线性关系良好,相关系数均大于0.999,方法定量限为0.01 mg/kg,平均回收率范围为77.0%~110%,相对标准偏差范围为1.45%~12.4%。结论 本方法简便、快速、准确、灵敏度高,适用于鸡组织和牛组织中甲苄喹啉和癸氧喹酯残留的检测与确证。     

液相色谱串联质谱法测定猪肉和猪尿中巴氯芬

样品中的巴氯芬用0.01 mol/L HCl溶液提取,提取液经WCX柱净化、富集后,进行液相色谱串联质谱(LC/MS-MS)分析.分析时采用BEH C18色谱柱(100mm×2.1mm,1.7μm),以0.10％甲酸水/甲醇作为流动相进行梯度洗脱,电喷雾正电子(ESI+)模式电离,多反应监测(MRM)模式检测,内标法进行定量.结果表明:巴氯芬标准溶液在1.0～100.0μg/L范围内,峰面积与含量呈线性相关.猪肉和猪尿中巴氯芬检出限分别为0.30μg/kg和0.10μg/L,两种样品中添加回收率在85％～110％之间,相对标准偏差(RSD)小于10％.     

多壁碳纳米管分散固相萃取结合LC-MS-MS测定鸡肉中金刚烷胺

建立了采用多壁碳纳米管为吸附剂的分散固相萃取净化、液相色谱串联质谱测定鸡肉中金刚烷胺残留量的方法。鸡肉样品经乙酸乙腈提取后,调节pH值至11,加入75 mg多壁碳纳米管进行分散固相萃取,被吸附的药物经5.0%甲酸溶液:甲醇(5∶5,V/V)洗脱,洗脱液过滤膜后直接进样分析。采用Acquity UPLC BEH C18色谱柱分离,以0.1%甲酸水溶液和甲醇作为流动相作梯度洗脱,电喷雾正电子(ESI+)模式电离,多反应监测模式检测,内标法校准进行定量。金刚烷胺在0.05~5.0μg/L质量浓度范围内呈良好的线性,线性相关系数均大于0.99,鸡肉样品中最低定量限为0.50μg/kg。鸡肉样品中添加0.5~1.0μg/kg金刚烷胺的回收率在97.8%~103.6%之间,相对标准偏差均小于10%。     

ELISA法与LC-MS/MS法测定动物组织中克仑特罗残留

目的:比较酶联免疫法(ELISA)和液相色谱-串联质谱法(LC-MS/MS)测定动物组织中克仑特罗残留量的准确度、精密度及检测限。方法:样品经过处理后,分别采用ELISA法和LC-MS/MS法进行测定;用ELISA法对组织样品进行初筛,测出阳性样品利用LC-MS/MS法进行确证。结果:应用ELISA法测定样品猪肉样品中克仑特罗的回收率为67.0%～99.6%,批内变异系数3.4%～8.7%,批间变异系数6.1%～9.6%,灵敏度为0.025μg/L,最低检测限0.025μg/kg;LC-MS/MS检测方法回收率88.62%～111.43%,批内变异系数4.4%～7.4%,最低检测限0.5μg/kg;用ELISA法对50份猪肉和50份猪肝样品进行检测,筛选出3个阳性样品,经LC-MS/MS确证为阳性,两种方法检测结果一致。结论:ELISA法灵敏度和准确度较高,样品处理方法简单,成本低,适合组织中克仑特罗残留大规模筛查;LC-MS/MS准确度高,适合于阳性样品精确定量。     

液相色谱-串联质谱法测定羊肉中的瘦肉精

利用液相-质谱串联法测定了市售羊肉中的瘦肉精残留量.氘代沙丁胺醇与克伦特罗混合内标溶液加入经酶解的样品中,用C18小柱净化后以3％的氨水甲醇溶液对Oasis MCX小柱进行洗脱,吹干,以0.1％甲酸水溶液-甲醇溶液(95:5)溶解残余物,用液相质谱串联连用法测定,以0.1％甲酸乙腈溶液和0.1％甲酸溶液为流动相梯度洗脱...     

Rapid screening method for quinolone residues in livestock and fishery products using immobilised metal chelate affinity chromatographic clean-up and liquid chromatography-fluorescence detection

An efficient LC method was developed for screening the presence of quinolones (QLs)--comprising fluoroquinolones (FQs) and acidic quinolones (AQs)--residues in various livestock and fishery products. Targeted analytes were for nine FQs of marbofloxacin (MAR), ofloxacin (OFL), norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENR), danofloxacin (DAN), orbifloxacin (ORB), difloxacin (DIF) and sarafloxacin (SAR), and three AQs of oxolinic acid (OXA), nalidixic acid (NAL) and flumequine (FMQ). Samples comprised ten different food products covering five matrices: muscle (cattle, swine and chicken), liver (chicken), raw fish (shrimp and salmon), egg (chicken), and processed food (ham, sausage and fish sausage). This method involved a simple extraction with (1:1) acetonitrile-methanol, a highly selective clean-up with an immobilised metal chelate affinity column charged with Fe(3+), a fast isocratic LC analysis using a short column (20 mm × 4.6 mm, 3 μm) with a mobile phase of (15:85:0.1) methanol/water/formic acid, and fluorescence detection (excitation/emission wavelengths of 295 nm/455 nm for FQs (495 nm for MAR), and 320 nm/365 nm for AQs). Among FQs, pairs of NOR/OFL, ORB/DIF and ENR/DAN were incompletely resolved. A confirmatory LC run with a Mg(2+) containing methanolic mobile phase was also proposed for the samples suspected of being positive. The optimised method gave satisfactory recoveries of 88.5% (56.1-108.6%) and 78.7% (44.1-99.5%) for intra- and inter-day assays with relative standard deviations of 7.2% (0.7-18.4%) and 6.8% (1.4-16.6%), respectively. Limits of quantitation ranged from 0.8 μg kg(-1) (DAN) to 6.5 μg kg(-1) (SAR). This method was successfully employed to analyse 113 real samples and two positive samples were found: fish sausage (CIP 990 μg kg(-1)) and shrimp (ENR 20 μg kg(-1)).     

牛肉、牛奶中可的松和氢化可的松含量分析

采用液相色谱-串联质谱技术分析我国部分地区市售牛肉、牛奶中可的松和氢化可的松的含量水平。均质的牛肉或牛奶样品在乙酸-乙酸钠缓冲液中酶解后用甲醇提取，提取液用石墨化碳黑固相萃取小柱和氨基固相萃取小柱净化，洗脱液氮吹至干并用甲醇溶液定容，液相色谱-串联质谱测定。采用SPSS?21.0软件进行数据分析。对采自我国9?省市的346?份牛肉和牛奶样品进行检测，分析牛肉和牛奶中可的松和氢化可的松的存在水平。牛肉和牛奶中均检出可的松和氢化可的松，检出率在86.1%～100.0%之间，检出含量范围为0.02～74.88?μg/kg。牛肉中可的松和氢化可的松的含量平均值（中位数）分别为1.69（1.14）?μg/kg和12.16（8.14）?μg/kg，牛奶中可的松和氢化可的松的含量平均值（中位数）分别为0.23（0.23）?μg/kg和0.72（0.72）?μg/kg。牛肉和牛奶中氢化可的松与可的松的含量均呈显著正相关。     

探索用液质串联联用法测定牛肉中的瘦肉精

目的:探索用液质串联联用法测定抽查牛肉中的瘦肉精含量。方法:酶解后的样品溶液,加入氘代克伦特罗与沙丁胺醇作为混合内标,过C18固相萃取小柱,用OasisMCX小柱收集,以3%的氨水甲醇溶液对MCX小柱进行洗脱后吹干,残余物溶于0.1%甲酸水溶液-甲醇溶液(95:5),以0.1%甲酸乙腈溶液和0.1%甲酸溶液为梯度流动相,上液质串联联用仪测定。结果:各β受体激动剂在0.5～5.0μg/kg浓度范围良好线性关系,平均回收率90.47%～102.58%,仪器定量限0.0543～0.2978μg/kg。结论:此方法极大排除了其他成分干扰,重现性好,专属性强,灵敏准确,可作检测牛肉中的瘦肉精残留量参考。     

快速滤过型净化结合液相色谱-质谱联用法测定海产品中19种磺胺类药物残留

建立了快速滤过型净化(m-PFC,multi-plug filtration cleanup)结合液相色谱-质谱联用技术同时检测海产品中19种磺胺类药物的分析方法。样品加水浸润后经过甲酸乙腈提取,QuEChERS盐包分层,取上层提取液经m-PFC柱净化,液相色谱-质谱联用测定,采用多反应监测模式(MRM)进行分析,基质外标法定量。结果表明,19种磺胺类药物在1～100μg/L的范围内线性关系良好,决定系数大于0.997,检出限为0.005～0.15μg/kg,定量限为0.01～0.41μg/kg。在10、20、100μg/kg三水平的平均添加回收率为70.0%～114.1%,相对标准偏差为0.5%～9.4%。该方法操作简便、快速,灵敏度高,重现性好,适用于海产品中多种磺胺类药物残留的检测。     

Simultaneous determination of quinolones in foods by LC/MS/MS

A simple method was developed for the simultaneous determination of seven quinolones (enoxacin, ofloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin and sarafloxacin) in foods using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The seven quinolones were extracted with acetonitrile containing 0.2% formic acid, and the extracted solution was cleaned up on a C18 cartridge. The extract was diluted with 5 mmol/L IPCC-MS3 for injection into the LC-ESI-MS/MS. The LC separation was carried out on an ODS column with gradient elution of 5 mmol/L IPCC-MS3-acetonitrile as the mobile phase. Mass spectral acquisition was done in the positive ion mode by applying selected reaction monitoring (SRM). The recoveries of the seven quinolones were mostly greater than 60% from foods fortified at 10 ng/g. The detection limits in foods were 2 ng/g for enoxacin and ciprofloxacin, and 1 ng/g for the other drugs. Twenty cattle muscle, 7 swine muscle, 9 chicken muscle, 16 milk, 19 prawn and 20 broiled eel samples from retail markets were analyzed by this method. Enrofloxacin and its metabolite ciprofloxacin were detected in 9 broiled eel at the level of trace (tr)-34 ng/g and tr-10 ng/g, respectively.     

Investigation of enrofloxacin residues in broiler tissues using ELISA and LC-MS/MS

This study investigated the efficiency of an enrofloxacin ELISA test kit to detect the presence of enrofloxacin residues in broiler tissues compared with LC-MS/MS. Broiler tissues from 72 samples consisting of 60 breast muscle, six pools of livers (500 g each) and six pools of kidneys (500 g each) were obtained from six different slaughterhouses. Breast muscle from 10 carcasses and pools of livers and kidneys from approximately 200 carcasses of the same flock were collected from each slaughterhouse. ELISA and HPLC were used to identify and quantify the contamination of the samples with enrofloxacin. A total of 72% of the analysed samples contained enrofloxacin residues detected by the ELISA and 22.2% were detected by LC-MS/MS. The mean values of enrofloxacin contamination found in chicken breast by ELISA and HPLC were 8.63 and 12.25 μg kg^–1, respectively. None of the samples exceeded the maximum limit of 100 μg kg^–1 by both methods set by the European Union as well as the Brazilian Agriculture Ministry. All positive samples for enrofloxacin residues detected by LC-MS/MS were also positive by ELISA. These data confirm the efficiency of the ELISA test, and suggest its use as a screening method for enrofloxacin residues in poultry tissues due to its quick results, low price and ease of applicability.     

通过型固相萃取净化-超高效液相色谱-串联质谱法检测鸡肉中23种磺胺类药物残留

建立了通过型固相萃取净化超高效液相色谱-串联质谱法同时检测鸡肉中23种磺胺类药物残留的分析方法。鸡肉样品经80%乙腈溶液（含0.2%甲酸）提取,Oasis PRiME HLB固相萃取柱进行净化,用Waters Acquity UPLC CSH C18色谱柱（100 mm×2.1 mm,1.7 μm）分离,以甲醇和0.1%甲酸溶液为流动相梯度洗脱,电喷雾源正离子扫描及依赖保留时间的多反应监测模式下（Scheduled MRM）检测,外标法定量。结果表明:23种磺胺类药物在线性范围0.2~20 ng/mL上有良好的线性关系,相关系数均大于0.9996;检出限为0.1~2.0 μg/kg,定量限为0.25~5.0 μg/kg;在1.0、2.0、5.0 μg/kg三个加标水平上平均回收率为66.12%~99.83%,相对标准偏差（RSD,n=6）为0.72%~10.36%;该方法操作简单、灵敏度高、重现性好,适用于鸡肉中多种磺胺类药物残留的检测。     

Determination method for ractopamine in swine and cattle tissues using LC/MS

Simple and reliable methods using LC/MS have been developed for the determination of the beta-agonist ractopamine in swine and cattle tissues. Ractopamine was extracted with ethyl acetate from muscle and liver, and the ethyl acetate layer was evaporated to dryness. The residue was purified by partition with acetonitrile/n-hexane. In the case of fat, ractopamine was extracted and purified by partition with acetonitrile/n-hexane. The resulting acetonitrile solutions were evaporated to dryness. The residue was dissolved in methanol, and subjected to LC/MS. The LC separation was performed on a Wakosil-II 3C18HG column (150 x 3 mm i.d.) in isocratic mode with 0.05% trifluoroacetic acid-acetonitrile (80:20) as a mobile phase at a flow rate of 0.4 mL/min. The MS detection was performed in the selected ion recording (SIR) mode, with detection of the M + H+ ion of ractopamine (m/z 302) produced by electrospray ionization (ESI). The mean recoveries of the drug from swine muscle (0.01 microg fortified), fat (0.01 microg fortified) and liver (0.04 microg/g fortified) were 99.7%, 99.5% and 100.8%, and those from cattle samples were 108.3%, 97.0% and 109.4%, respectively. The relative standard deviations (RSDs) ranged from 0.1% to 9.5%. The limit of quantification (LOQ) of the drug was 1 ng/g.     

液相色谱-串联质谱法测定畜禽表皮中松香酸和脱氢松香酸

采用液相色谱-串联质谱法对畜禽表皮组织中的松香酸和脱氢松香酸含量进行检测。样品中的松香酸和脱氢松香酸用乙腈提取,经HLB固相萃取柱净化,采用液相色谱-串联质谱进行检测。色谱柱：反相C18柱（100 mm×2.1 mm,2 μm）;流动相：0.1%甲酸溶液和0.1%甲酸-甲醇溶液（10∶90,V/V）;流速：0.3 mL/min;质谱分析采用电喷雾电离正离子模式检测,扫描方式为多反应监测。结果表明：松香酸线性范围为2.0～100 μg/L,检出限为1.1 μg/kg,定量限为3.6 μg/kg;脱氢松香酸线性范围为5.0～250 μg/L,检出限为3.9 μg/kg,定量限为13 μg/kg。在5.0～200 μg/kg添加量范围内松香酸和脱氢松香酸的回收率为81.7%～93.7%,相对标准偏差均在12%以内。方法用于实际样品分析,多个畜禽表皮样品中检出松香酸及脱氢松香酸,采用松香甘油酯进行脱毛的鸭皮中也检出了一定含量的松香酸及脱氢松香酸。本实验建立的分析方法简便快捷,具有较好的灵敏度和可靠性,可用于畜禽表皮组织中松香酸和脱氢松香酸的定量确证分析。     

Simultaneous analysis of four sulfonamides in chicken muscle tissue by HPLC

The aim of this study was to develop a simple high-performance liquid chromatography (HPLC) with UV detection method for the determination of four sulfonamides in chicken muscle tissue. The sulfonamides were extracted with acetonitrile, acetone and dichloromethane. Separation was carried out on a C18 column using as the mobile phase a mixture of 6‰ disodium hydrogen phosphate and methanol. The analytes were detected by UV in one run. Calibration curves were linear with very good correlation coefficients for concentration ranging from 30 to 150?μg?kg(-1). The limits of detection (LOD) for sulfonamides ranged from 6.5 to 0.14?μg?kg(-1). The recovery for spiked chicken muscle with 50-150?μg?kg(-1) was more than 70%. The relative standard deviations (RSDs) of the sulfonamides for six measurements at 50, 100 and 150?μg?kg(-1) were less than 15%. These parameters met the European Union criteria for method validation. The results were confirmed by LC-MS/MS using multiple reaction monitoring as the operating mode. Confirmation required the retention times of the analytes to be within ±2.5% of the retention times of the standards, the presence of the parent ion and two characteristic fragment ions (product ions) per analyte, as well as the relative ion abundance ratios of the fragment ions corresponding to ratios obtained for the standards, within permitted limits. The transition of two common product ions at m/z 155.7 and 107.5 were monitored for all sulfonamides. Each of the analytes, in all tested samples, met the confirmation criteria. Thus, the applicability of the HPLC-UV method for routine analysis of chicken muscle tissue was demonstrated.     

Determination of vedaprofen in livestock products and seafoods by liquid chromatography-tandem mass spectrometry

A novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the trace residue determination of vedaprofen (VPF) in livestock products and seafoods. VPF was extracted from each sample with acidified acetone, and the crude extract was re-extracted with ethyl acetate and NaCl solution. Clean-up was performed using a weak anion exchange cartridge (Bond Elut DEA). The LC separation was performed on a C18 column using acetonitrile-0.0025 mol/L formic acid (3 : 2) as the mobile phase and MS was run in the negative ion electrospray ionization mode. The calibration curve was linear in the range of 0.001-0.1 μg/mL VPF. The mean recoveries from equine muscle, cattle muscle, cattle liver, cattle fat, salmon, eel, corbicula, milk, egg and buckwheat honey were 72-94%, and the relative standard deviations (RSDs) were 1.1-2.0%. Limits of quantitation (LOQs) ranged from 0.001 to 0.007 μg/g.     

Analytical method of cereulide in processed cereal-based foods and milk powder by LC-MS/MS

An LC-MS/MS method for analysis of cereulide, an emetic toxin produced by Bacillus cereus, was developed. Cereulide was extracted from samples, fried rice, pan-fried noodles, red bean paste and baby formula, with methanol and purified using Oasis HLB cartridges. LC separation was performed on a C18 column with a mixture of formic acid solution and methanol containing ammonium formate as a mobile phase, and the mass spectrometer was operated in the positive electrospray ionization mode. Performance evaluation showed that trueness was higher than 70% and repeatability and reproducibility were within 10%. The limits of quantification were lower than 1 μg/kg.     

Rapid multiresidue determination of pesticides in livestock muscle and liver tissue via modified QuEChERS sample preparation and LC-MS/MS

ABSTRACT

Many multiresidue methods for the determination of pesticides in vegetables and fruits have been reported to date. However, few such methods have been employed to investigate pesticide residues in animal tissue. In this study, an LC-MS/MS multiresidue method coupled with modified QuEChERS extraction was developed and validated for the investigation of eight pesticide residues: prallethrin (PR), resmethrin (RMT), imidacloprid (IMC), diflubenzuron (DFB), cyromazine (CYR), etofenprox (EFP), dinotefuran (DNT) and phthalthrin (PTLT). This method involves initial extraction in a water/acetone system, the addition of salts and a subsequent extraction/partitioning step and, finally, a clean-up step utilising dispersive solid-phase extraction (SPE). The mean recoveries of seven of the pesticides (the exception being CYR) ranged between 74.7% and 113.5%, and the CVs of the livestock tissue – bovine, swine, and chicken muscle and liver tissue spiked at 10 ng g^–1 (50 ng g^–1 for RMT and DNT) and 100 ng g^–1 – were < 13.8%. The recoveries of CYR in all muscle and liver spiked samples ranged from 56.9% to 78.3%, while those of RMT in swine liver were > 120%. Therefore, this method was considered as being unsuitable for the investigation of these samples. The limits of quantitation (LOQs) of seven of the investigated pesticides (the exception being swine liver) in the tissue samples ranged from 0.9 to 15.2 ng g^–1. We therefore concluded that this LC-MS/MS multiresidue method is a valid and suitable for the investigation of seven pesticides in animal tissue, but it is unsuitable for the analysis of CYR in all animal tissues and RMT in swine liver tissue.     

GC-MS和LC-MS/MS分析麦粉中烷基间苯二酚同系物组成

建立气相色谱-质谱（gas chromatography-mass spectrometry,GC-MS）联用法和液相色谱-串联质谱（liquid chromatography-tandem mass spectrometry,LC-MS/MS）法测定麦粉中烷基间苯二酚组成。样品经乙酸乙酯超声提取,在GC-MS中,硅烷化衍生处理,采用选择离子监测模式进行测定,以外标法进行定量;在LC-MS/MS中,经固相萃取富集净化,以C18色谱柱分离,采用电喷雾负离子模式扫描、多反应监测模式检测,以外标法进行定量。结果表明,GC-MS和LC-MS/MS均在0.001～5 μg/mL质量浓度范围内有良好的线性关系（R2＞0.98）,GC-MS法的检出限为2.0～6.1 μg/g,加标回收率在94.17%～99.15%之间,相对标准偏差（relative standard deviation,RSD）在2.94%～4.87%之间;LC-MS/MS法的检出限为2.0～8.4 μg/g,加标回收率在89.05%～99.06%之间,RSD在2.21%～4.17%之间。本研究建立了2 种线性关系良好、低检测限、高灵敏度的检测方法,均可适用于市售麦粉产品中烷基间苯二酚同系物定性定量分析,将为麦类全谷物产品品质控制与检测提供技术指导。