Use of gas liquid chromatography/mass spectrometry for triazine herbicide residues analysis in forage and milk

Residual s-triazines were isolated from forage and milk samples by methanol/chloroform extraction followed by column purification. The evaporated extracts were dissolved in acetone and analysed by gas chromatography with NPD detection and mass spectrometry. The detection limits for both methods were found to be about 5 approximately 10 ng of each s-triazine. The selective ions of the 10 s-triazines investigated (simazine, atrazine, propazine, terbuthylazine, cyanazine, desmetryne, ametryne, prometryne, terbutryne and methoprotryne) were chosen on the basis of an electron impact mass spectrometry study of the s-triazine standards and the whole mass spectra are given. Special attention was paid to the fragmentation of cyanazine and the general cleavage pathways of the s-triazines under investigation.     

Determination of herbicide residues in olive oil by gas chromatography–tandem mass spectrometry

This paper reports a method for the analysis in olive oil of multiresidues of the herbicides of low-medium polarity most widely used by Andalusian olive growers. The method, which uses gas chromatography/tandem mass spectrometry (GC–MS/MS), was developed within the framework of Project CAO00-005, which spanned the period from 2000 to 2004. The results obtained for more than 3000 samples of virgin olive oil and organic olive oil analyzed over such a period are reported. Samples were extracted with an acetonitrile/n-hexane mixture and cleaned up by passage through Florisil columns prior to analysis. A linear determination range for the herbicides from 1 to 500 μg kg⁻¹ and a correlation coefficient better than 0.996 were achieved. The reproducibility, as relative standard deviation, was quite acceptable (8–11%), and so were herbicide recoveries (90–102%). The proposed method has been transferred to both public and private laboratories in the Andalusian region.     

液相色谱-串联质谱法检测牛乳中多肽类抗生素残留量

选用牛奶为研究对象,建立了一种可同时测定多粘菌素B、粘杆菌素、杆菌肽和维吉尼霉素等4种多肽类抗生素残留量的液相色谱-串联质谱法(LC-MS/MS)检测方法.样品经甲醇-0.1%甲酸体系提取,正己烷脱脂,固相萃取柱净化后,利用LC-MS/MS进行定性和定量分析.结果表明,该方法4种多肽类抗生素检出限分别为:多粘菌素B 250 μg/kg,粘杆菌素25 μg/kg,杆菌肽A 50 μg/kg,雏吉尼霉素 20μg/kg.平均回收率分别为:多粘菌素B 92.16%-95.89%,粘杆菌素92.24%-97.87%,杆菌肽94.54%-97.96%,维吉尼霉素93.58%-98.25%.变异系数为2.54-6.55.     

Multiclass methods for the analysis of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry: A review

Milk is an important and beneficial food from a nutritional point of view, being an indispensable source of high quality proteins. Furthermore, it is a raw material for many dairy products, such as yoghurt, cheese, cream etc. Before reaching consumers, milk goes through production, processing and circulation. Each step involves potentially unsafe factors, such as chemical contamination that can affect milk quality. Antibiotics are widely used in veterinary medicine for dry cow therapy and mastitis treatment in lactating cows, which can cause the presence of antimicrobial residues in milk. In order to ensure consumers’ safety, milk is analyzed to make sure that the fixed Maximum Residue Limits (MRLs) for antibiotics are not exceeded. Multiclass methods can monitor more drug classes through a single analysis, so they are faster, less time-consuming and cheaper than traditional methods (single-class); this aspect is particularly important for milk, which is a highly perishable food. Nevertheless, multiclass methods for veterinary drug residues in foodstuffs are real analytical challenges. This article reviews the major multiclass methods published for the determination of antibiotic residues in milk by liquid chromatography coupled to mass spectrometry, with a special focus on sample preparation approaches.     

高效液相色谱串联质谱法快速测定牛奶中地塞米松残留量

目的建立高效液相色谱串联质谱法快速有效检测牛奶中地塞米松残留量的分析方法。方法样品经乙腈提取,正己烷萃取去除杂质后,取乙腈层旋转蒸发至近干,用20%乙腈水溶液溶解后,经C_(18)色谱柱分离,以甲醇-水(9:1,V:V)为流动相,应用高效液相色谱串联质谱仪在电喷雾负离子模式(electron spray ionization,ESI-)下采用多反应监测(multiple reaction monitoring,MRM)方式对牛奶中地塞米松进行定性及定量分析。结果地塞米松在5～100 ng/mL范围内呈良好的线性关系,方法检出限为0.19μg/kg(S/N=3),不同水平的加标回收率在85%～107.2%之间,相对标准偏差在0.84%～1.22%之间(n=3)。结论该方法具有快速、简便、准确、灵敏的特点,适用于牛奶中地塞米松残留量的分析检测,可用于日常大批量快速筛查工作,有效提高日常工作效率。     

Development and application of pyrolysis gas chromatography/mass spectrometry for the analysis of bound trinitrotoluene residues in soil

TNT (trinitrotoluene) is a contaminant of global environmental significance, yet determining its environmental fate has posed longstanding challenges. To date, only differential extraction-based approaches have been able to determine the presence of covalently bound, reduced forms of TNT in field soils. Here, we employed thermal elution, pyrolysis, and gas chromatography/mass spectrometry (GC/MS) to distinguish between covalently bound and noncovalently bound reduced forms of TNT in soil. Model soil organic matter-based matrixes were used to develop an assay in which noncovalently bound (monomeric) aminodinitrotoluene (ADNT) and diaminonitrotoluene (DANT) were desorbed from the matrix and analyzed at a lower temperature than covalently bound forms of these same compounds. A thermal desorption technique, evolved gas analysis, was initially employed to differentiate between covalently bound and added 15N-labeled monomeric compounds. A refined thermal elution procedure, termed "double-shot analysis" (DSA), allowed a sample to be sequentially analyzed in two phases. In phase 1, all of an added 15N-labeled monomeric contaminant was eluted from the sample at relatively low temperature. In phase 2 during high-temperature pyrolysis, the remaining covalently bound contaminants were detected. DSA analysis of soil from the Louisiana Army Ammunition Plant (LAAP; approximately 5000 ppm TNT) revealed the presence of DANT, ADNT, and TNT. After scrutinizing the DSA data and comparing them to results from solvent-extracted and base/ acid-hydrolyzed LAAP soil, we concluded that the TNT was a noncovalently bound "carryover" from phase 1. Thus, the pyrolysis-GC/MS technique successfully defined covalently bound pools of ADNT and DANT in the field soil sample.     

液相色谱-串联质谱法测定牛奶中米尔贝霉素类药物残留

目的应用液相色谱-串联质谱技术,建立牛奶中奈马克丁、米尔贝霉素A3、米尔贝霉素A4、米尔贝霉素D和莫西丁克等5种米尔贝霉素类药物残留检测方法。方法用乙腈提取牛奶样品中的目标物,C18固相萃取柱净化,Agilent Poroshell 120 EC-C18色谱柱分离,以0.1%甲酸水溶液和甲醇为流动相梯度洗脱,然后用液相色谱-串联质谱仪在正离子多反应监测(MRM)模式下测定。结果 5种化合物在10~100μg/kg范围内线性良好,相关系数大于0.99,平均回收率为77.5%~100%,相对标准偏差小于11.6%。结论 本方法灵敏度高,重现性好,适用于牛奶中米尔贝霉素类药物残留检测。     

液相色谱-串联质谱法测定牛奶中米尔贝霉素类 药物残留

目的 应用液相色谱-串联质谱技术,建立牛奶中奈马克丁、米尔贝霉素A3、米尔贝霉素A4、米尔贝霉素D和莫西丁克等5种米尔贝霉素类药物残留检测方法。方法 用乙腈提取牛奶样品中的目标物,C18固相萃取柱净化,Agilent Poroshell 120 EC-C18色谱柱分离,以0.1%甲酸水溶液和甲醇为流动相梯度洗脱,然后用液相色谱-串联质谱仪在正离子MRM模式下测定。结果 5种化合物在10-100 μg/kg范围内线性良好,相关系数大于0.99,平均回收率为77.5%~100%,相对标准偏差小于11.6%。结论 本方法灵敏度高,重现性好,完全适用于牛奶中米尔贝霉素类药物残留检测。     

气相色谱质谱联用法检测牛奶及奶粉中肌醇

利用70%的乙醇从样品中提取肌醇,然后采用硅烷化试剂(三甲基氯硅烷∶六甲基二硅胺烷∶N,N二甲基甲酰胺=1∶2∶8)进行衍生,通过GC/MS进行检测。通过全扫描确定,特征离子的m/z73.0、147.0、191.1、217.1、305.2为定性离子,其中m/z73.0为定量离子。方法线性关系良好,相关系数为0.9987,方法检出限为9μg/100g,RSD分别为7.997%、2.515%、2.529%(n=7),方法的回收率在88.5%～108.1%之间,均能满足样品检测的要求。      

防虫蛀纯羊毛绒线中Permethrin残留量的GC/MS测定

毛绒织物样品以1：1丙酮－正己烷混合溶剂超声提取后，提取液经Celite层析柱净化，40℃旋转蒸发浓缩、定容，由色－质联用仪测定试样中的氯菊酯（Permethrin)含量。本方法对目标化合物的检测限量在0．1－0．5mg/kg范围内，平均回收率介于89．1％－101．2％之间，相对标准偏差为2．3％－4．4％。     

Pesticide residues in fruits and vegetables in Jordan using liquid chromatography/tandem mass spectrometry

A total of 158 fruit and vegetable samples produced in Jordan were examined for the presence of pesticide residues using the multi-residue analysis technique by Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) and the QuEchERS extraction method. A total of 73 samples (46%) were free from detectable residues, while 85 samples (54%) contained residues. Among the tested samples, 34 (22%) contained residues above Maximum Residue Levels (MRLs) and 51 (32%) contained residues at or below MRLs. Most of the detected residues were found in sweet pepper, peach and apricot samples. Only watermelon samples were free from detectable residues, while tomato and melon samples exhibited residues below MRLs. Out of the 113 pesticides tested, 22 pesticides were found above the limit of detection, 9 of which (hexaconazole, propargite, propiconazole, myclobutanil, thiamethoxam, thiacloprid, clothianidin, clofentezine and pyridaben) had residues that violate MRLs according to European regulations. A continuous monitoring programme for pesticide residues in Jordanian fruits and vegetables is highly recommended.     

Analyses of selected non-authorized insecticides in peppers by gas chromatography/mass spectrometry and gas chromatography/tandem mass spectrometry

Two methods based on gas chromatography coupled with mass spectrometry and tandem mass spectrometry analyzers are described for the identification, confirmation and quantitation of two EU-banned insecticides: isocarbophos and isofenphos-methyl, detected in recent monitoring programmes in pepper samples. The proposed methodologies involved a liquid–liquid extraction with acetonitrile followed by a cleanup step by dispersive solid-phase extraction using primary–secondary amine as sorbent material. Recovery studies performed on peppers spiked at different fortification levels (10 and 50 μg kg⁻¹) yielded average recoveries in the range 85–98% with RSD values below 8%. Identification, confirmation and quantitation were carried out by gas chromatography/mass spectrometry (GC–MS) in selected ion monitoring mode and gas chromatography/tandem mass spectrometry (GC–MS/MS) using an ion trap operating in the multiple reaction monitoring (MRM) mode. The obtained limits of detection (LODs) were in the range 0.1–0.3 μg kg⁻¹, depending on the technique. The proposed methods were successfully applied to the analysis of suspected pepper samples.     

通过式固相萃取与液相色谱串联质谱和气相色谱串联质谱结合测定加热卷烟中多种农药残留

[目的]实现加热卷烟中多种农药残留的测定.[方法]样品经乙腈提取,以PRiME HLB通过式固相萃取柱净化后,分别以液相色谱-串联质谱(LC-MS/MS)和气相色谱-串联质谱(GC-MS/MS)分析.[结果]①PRiME HLB通过式固相萃取净化效率高,操作简便.②在高、中、低三个不同添加浓度水平下,所有分析物的回收率...     

Quantitative analysis of pesticide residues in vegetables and fruits by liquid chromatography quadrupole time-of-flight mass spectrometry

The applicability of liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) for the quantitative analysis of pesticide residues in vegetables and fruits was demonstrated. The LC-QTOF-MS parameters, such as cone voltage, capillary voltage, collision energy and mass extraction window, were carefully optimised for the analysis of pesticide residues. The LC-QTOF-MS method was validated for 149 pesticides in four vegetables and fruits, i.e. apple, potato, cabbage and spinach, at a spiking level of 0.01 mg kg^?1. The samples were prepared according to the Japanese official multi-residue method with a modification to the column clean-up procedure. Of the 149 pesticides, recoveries in the range of 70–120% were achieved for 147 pesticides in apple, 145 in potato, 141 in cabbage and 131 in spinach, with intra-day precisions (RSDs) of < 25% and inter-day precisions (RSDs) of < 30%, which are within the acceptable range given in the Japanese method validation guideline. Matrix effects were negligible for the majority of the target pesticides. Except for spiroxamine in spinach, no interfering peaks were observed in the blank samples. The target pesticides, except those with low sensitivity, achieved calibration curves with satisfactory linearity, with correlation coefficients (r) greater than 0.995 in the concentration range of 0.002–0.1 μg ml^?1. Furthermore, the majority of the target pesticides provided more than one fragment ion or isotope ion that could be used for confirmation. The overall results suggest that LC-QTOF-MS is a powerful tool for the quantification of pesticide residues in vegetables and fruits at the level of 0.01 mg kg^?1.     

液相色谱-串联质谱法测定牛奶和奶粉中6种大环内酯类药物的残留量

建立了液相色谱串联质谱测定牛奶和奶粉中6种大环内酯类药物(螺旋霉素、吡利霉素、竹桃霉素、替米卡星、红霉素和泰乐菌素)残留量的分析方法。采用乙腈提取目标物,OasisHLB固相萃取柱净化提取液,液相色谱-串联质谱测定,外标法定量。牛奶中6种大环内酯类药物的检测低限(LOQ)为1μg/kg,奶粉的LOQ为8μg/kg。6种分析物在0～100μg/L的浓度范围内呈良好线性,线性相关系数>0.992。方法在三个水平的添加回收率在81.5%～96.1%之间,相对标准偏差在3.29%～9.96%之间。方法回收率高、重现性好,适用于牛奶、奶粉等样品中大环内酯类药物残留的定量及确证检测。     

超高效液相色谱-串联质谱法测定乳及乳制品中苯菌酮的残留量

目的 建立了一种超高效液相色谱-串联质谱法（ultra performance liquid chromatography-tandem mass spectrometry, UPLC-MS/MS）对乳及乳制品中苯菌酮的残留量进行定量的检测方法。方法 样品经1%甲酸乙腈提取,经Prime HLB固相萃取小柱净化,以ACQUITY UPLC BEH Phenyl 色谱柱（2.1 mm×100 mm, 1.7 μm）分离,使用乙腈-0.1%甲酸水作为流动相进行梯度洗脱,扫描方式在电喷雾离子源正离子模式下采用多反应监测（multiple reaction monitoring, MRM）模式,采用基质匹配标准曲线校准,外标法定量。结果 苯菌酮在1.0-200.0 μg/L范围内线性关系良好,相关系数（r）均不小于0.996。方法检出限及方法定量限分别为1.5 μg/kg与5.0 μg/kg。在3个添加水平的加标回收实验下,苯菌酮的平均回收率为84.1%~107.5%,相对标准偏差为1.0%~7.2%（n=6）。结论 本方法前处理操作简便,结果准确,灵敏度高,适用于乳及乳制品中苯菌酮残留量的测定。     

液相色谱-串联质谱法测定茶叶中二氰蒽醌残留量

目的建立液相色谱-串联质谱法(liquidchromatographytandemmassspectrometry,LC-MS/MS)测定茶叶中二氰蒽醌残留。方法茶叶用乙腈(含0.1%甲酸)提取,经固相萃取柱(HC-C18 SPE)净化后采用多反应监测(multiplereactionmonitoring,MRM)模式进行检测,外标法定量。结果目标化合物在一定范围内(0.391～12.5μg/L)线性关系良好,相关系数(r2)大于0.995。样品中二氰蒽醌的定量限(limitofquantification,LOQ)和检出限(limitofdetection,LOD)分别为10.0、5.00μg/kg;不同加标浓度样品10.0μg/kg(LOQ)、20.0μg/kg(2×LOQ)、50.0μg/kg(5×LOQ)的平均回收率为84.1%～103%,相对标准偏差(RSDs)为3.18%～4.62%。25份市售茶叶中均未检出二氰蒽醌。结论该方法简便、快速,准确。各项性能参数均能符合技术规范的要求,已应用于市售茶叶的检测。     

液相色谱-串联质谱法测定发酵乳中爱德万甜的含量

目的建立液相色谱-串联质谱法(liquid chromatography tandem mass spectrometry,LC-MS-MS)测定发酵乳中爱德万甜含量的方法。方法样品经1%高氯酸水溶液超声提取,提取液通过Oasis HLB固相萃取柱净化,经Agilent Zorbax XDB C_(18)色谱柱分离,流动相0.1%甲酸水溶液和乙腈洗脱,然后采用电喷雾串联质谱进行定性和定量分析。结果爱德万甜在5~200μg/L浓度范围内线性关系良好,相关系数大于0.99,爱德万甜的检出限(S/N=3)为1.5μg/kg,定量限(S/N=10)为5.0μg/kg,在5.0~500.0μg/kg的加标范围内,回收率为92.1%~101.6%,相对标准偏差为2.57%~4.56%。结论本方法前处理简单、灵敏度高,适用于发酵乳中爱德万甜含量的测定。