GC-MS/MS同时测定杭白菊中68种农药残留

目的 采用GC-MS/MS建立同时测定杭白菊中68种农药残留的分析方法。方法 样品采用QuEChERS前处理程序,经1%冰醋酸浸泡30 min后,乙腈提取,经装有无水硫酸镁900 mg、PSA 300 mg、十八烷基键合硅胶300 mg、硅胶300 mg和石墨化炭黑90 mg的分散固相萃取净化管净化,采用GC-MS/MS动态多反应监测模式,进行定性定量分析。结果 68种农药在各自浓度范围内线性关系良好,相关系数r均>0.993。在20,100,200 μg·kg^-1 3个不同加标水平下,除六氯苯、甲基五氯苯硫醚、苯氟磺胺、p,p''-滴滴伊和氯氟氰菊酯外,大部分农药的回收率均在70.0%~120.0%之间,RSD在0.4%~13.9%之间。方法的检出限为0.2~25.6 μg·kg^-1,定量限为0.8~85.5 μg·kg^-1。结论 该方法简单、快速、高效、灵敏,可为杭白菊中多农药残留的快速筛查和测定提供一种有效的分析手段。     

Simultaneous analysis of mycotoxins in corn flour using LC/MS-MS combined with a modified QuEChERS procedure

The present study was developed to simultaneously quantify different mycotoxins including zearalenone (ZEA), T2-toxin, aflatoxin B1 (AFB₁), deoxynivalenol (DON), and ochratoxin A (OTA) in 30 and 10 corn flour samples collected from local gristmill corn in Ardabil province and local markets in Tehran, respectively. A modified method QuEChERS (quick, easy, cheap, effective, rugged, and safe) in combination with an LC-MS/MS technique was used for sample preparation and measuring the levels of mycotoxins, respectively. Spiked calibration curves based on external and internal standards were used to overcome matrix effects and were reported as linear between 2 and 50?ng g^?1 for aflatoxin B1, T-2 toxin, ochratoxin A; 50 and 1250?ng g^?1 for zearalenone; and 75 and 1800?ng g^?1 for deoxynivalenol. With the aid of spike calibration curves and acidic condition, the absorption of OTA by primary, secondary amine was reduced, and consequently, the percentage of recoveries was improved (in the range of 92.98–103.8). AFB₁, OTA, and ZEA were detected and quantified in 23 (76.6%), 6 (20%), and 14 (46%) of 30 samples, with average contamination of 154.1?ng g^?1, 25?ng g^?1, and 358.7?ng g^?1, respectively. The co-occurrence of AFB₁?+?ZEA and AFB₁?+?OTA?+?ZEA was noted in 20% and 23% of corn samples, respectively. The measured level of contamination for DON and T-2 toxin of corn flour samples did not exceed the maximum tolerated level. Moreover, the estimation of dietary intake of AFB₁, OTA, ZER, DON, and T2-toxin were 5.8, 1.1, 32.1, 5.58, and 0.06?ng per kg body weight per day, respectively.     

QuEChERS结合UHPLC-MS同时测定土鳖虫及其成方制剂中9种真菌毒素含量

目的:建立QuEChERS结合超高效液相色谱-串联质谱法(UHPLC-MS)同时测定6种含土鳖虫的成方制剂中9种真菌毒素的方法。方法:样品用QuEChERS方法进行前处理,经10%甲酸乙腈提取,用N-丙基-乙二胺硅烷和无水硫酸镁进行净化,采用UHPLC-MS在多反应监测模式下进行测定,外标法定量。结果:9种真菌毒素的含量在各自质量浓度范围内具有较好的线性关系(r≥0.9956),目标化合物在低、中、高3个质量浓度下的平均回收率为70.42%~101.28%,RSD<12%,定量限(LOQ)为1.2~18.6μg·kg^(–1)。结论:该方法灵敏度高、准确性好,适合于土鳖虫及其成方制剂中9种真菌毒素的测定。     

Postmortem distribution of α-pyrrolidinobutiophenone in body fluids and solid tissues of a human cadaver

We experienced an autopsy case of a 21-year-old male Caucasian, in which the direct cause of his death was judged as subarachnoid hemorrhage. There was cerebral arteriovenous malformation, which seemed related to the subarachnoid hemorrhage. The postmortem interval was estimated to be about 2 days. By our drug screening test using gas chromatography–mass spectrometry, we could identify α-pyrrolidinobutiophenone (α-PBP) in his urine specimen, which led us to investigate the postmortem distribution of α-PBP in this deceased. The specimens dealt with were right heart blood, left heart blood, femoral vein blood, cerebrospinal fluid, urine, stomach contents and five solid tissues. The extraction of α-PBP and α-pyrrolidinovalerophenone (α-PVP, internal standard) was performed by a modified QuEChERS (quick, easy, cheap, effective, rugged and safe) method, followed by the analysis by liquid chromatography–tandem mass spectrometry. Because this study included various kinds of human matrices, we used the standard addition method to overcome the matrix effects. The highest concentration was found in urine, followed by stomach contents, the kidney, lung, spleen, pancreas and liver. The blood concentrations were about halves of those of the solid tissues. The high concentrations of α-PBP in urine and the kidney suggest that the drug tends to be rapidly excreted into urine via the kidney after its absorption into the blood stream. The urine specimen is of the best choice for analysis. This is the first report describing the postmortem distribution of α-PBP in a human to our knowledge.     

Simultaneous Detection of Seven Alternaria Toxins in Mixed Fruit Puree by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry Coupled with a Modified QuEChERS

The presence of Alternaria toxins (ATs) in fruit purees may cause potential harm to the life and health of consumers. As time passes, ATs have become the key detection objects in this kind of food. Based on this, a novel and rapid method was established in this paper for the simultaneous detection of seven ATS (tenuazonic acid, alternariol, alternariol monomethyl ether, altenuene, tentoxin, altenusin, and altertoxin I) in mixed fruit purees using ultra-high performance liquid chromatography-tandem mass spectrometry. The sample was prepared using the modified QuEChERS (quick, easy, cheap, effective, rugged, and safe) method to complete the extraction and clean-up steps in one procedure. In this QuEChERS method, sample was extracted with water and acetonitrile (1.5% formic acid), then salted out with NaCl, separated on an ACQUITY UPLC BEH C₁₈ with gradient elution by using acetonitrile and 0.1% formic acid aqueous as eluent, and detected by UPLC-MS/MS under positive (ESI⁺) and negative (ESI⁻) electrospray ionization and MRM models. Results showed that the seven ATs exhibited a good linearity in the concentration range of 0.5–200 ng/mL with R² > 0.9925, and the limits of detection (LODs) of the instrument were in the range of 0.18–0.53 μg/kg. The average recoveries ranged from 79.5% to 106.7%, with the relative standard deviations (RSDs) no more than 9.78% at spiked levels of 5, 10, and 20 μg/kg for seven ATs. The established method was applied to the determination and analysis of the seven ATs in 80 mixed fruit puree samples. The results showed that ATs were detected in 31 of the 80 samples, and the content of ATs ranged from 1.32 μg/kg to 54.89 μg/kg. Moreover, the content of TeA was the highest in the detected samples (23.32–54.89 μg/kg), while the detection rate of Ten (24/31 samples) was higher than the other ATs. Furthermore, the other five ATs had similar and lower levels of contamination. The method established in this paper is accurate, rapid, simple, sensitive, repeatable, and stable, and can be used for the practical determination of seven ATs in fruit puree or other similar samples. Moreover, this method could provide theory foundation for the establishment of limit standard of ATs and provide a reference for the development of similar detection standard methods in the future.     

全自动样品前处理技术在中药禁用农药残留检测中应用

目的 将全自动样品前处理平台应用于中药农药残留的检测，探索其替代手动处理完成实验流程的可行性。方法 选择人参、金银花、枸杞3种不同种类药材，通过手动和自动QuEChERS方法对样品进行前处理，通过气相色谱-质谱联用仪(GC-MS/MS)对35种禁用农药残留进行检测。结果 35种农药中人参基质的手动与自动回收率显著性差异的成分占88.6%，金银花基质为37.1%，枸杞基质为4.3%，其中超过80%的农药是自动回收率大于手动，其余农药手动和自动的回收率无显著性差异。在3种不同基质下，35种农药在考察的浓度范围内均呈良好的线性关系(r>0.990)，除杀虫脒外，其他农药在3种基质中的回收率为70.05%~112.54%，RSD为0.3%~9.8%。结论 全自动QuEChERS方法高效，准确，可应用于中药农药残留的检测。