UHPLC-LTQ Orbitrap MS测定鸡肉组织中5种糖皮质激素残留

建立了鸡肉组织中地塞米松、泼尼松、氢化可的松、甲基氢化泼尼松、曲安那德5种糖皮质激素的QuEChERS前处理方法以及超高效液相色谱-高分辨质谱（UHPLC-LTQOrbitrapMS）检测方法。对QuEChERS前处理条件进行优化,结果表明,以乙酸乙酯为提取溶剂,乙二胺-N-丙基（PSA）为净化吸附剂,可达到最佳提取和净化效果。采用WatersAQUITYUPLCHSST3（2.1mm×150mm,1.8μm）色谱柱进行分离,以乙腈-0.1%甲酸水溶液为流动相,梯度洗脱,流速为250μL/min。通过LTQOrbitrapMS质谱检测器进行检测,以保留时间和精确质量数进行定性,母离子的峰面积进行定量。5种糖皮质激素的线性范围为1~100μg/L,相关系数均大于0.99,在5、10、20μg/kg3个加标水平下的回收率为87.5%~119.7%,相对标准偏差（RSDs）为2.0%~11.0%。5种糖皮质激素的检出限（LODs）为0.49~0.78μg/kg,定量下限（LOQs）为1.62~2.57μg/kg。该方法稳定、可靠,可满足鸡肉中地塞米松等糖皮质激素残留的检测与确证要求。     

超高效液相色谱-高分辨率质谱法筛查化妆品中12种糖皮质激素

建立了超高效液相色谱-四极杆-静电场轨道阱质谱快速筛查和确证化妆品中可能添加的12种糖皮质激素的分析方法。样品经乙腈提取,用AcquityUPLCBEHC18柱（100mm×2.1mm,1.7μm）分离,以0.1%甲酸甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱。以正离子全扫描模式得到糖皮质激素的精确质量数,与理论精确质量数对比,精确度偏差小于2×10-6。建立了筛查列表,并将12种糖皮质激素物质的二级质谱数据库加入确证条件中,实现了对12种糖皮质激素类物质的快速筛查。检出限为1~2μg/kg,定量下限为3~5μg/kg;加标水平为10,20,40μg/kg时,回收率为78.3%~112.5%,相对标准偏差（RSD）为1.0%~11.2%。该方法可作为化妆品中非法添加糖皮质激素成分的高通量筛选和确认检测方法。     

微波辅助萃取-超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法快速测定食品接触塑料制品中48种污染物残留

利用超高效液相色谱-四极杆/静电场轨道阱高分辨质谱法（UPLC-Q Orbitrap HRMS）的同时定性定量功能,建立了食品接触塑料制品中48种污染物残留的检测方法。用甲醇提取目标化合物,经微波辅助萃取,采用CAPCELL PAK MG Ⅱ C18色谱柱（150 mm×2.0 mm,5 μm）分离,以0.04%（v/v）甲酸甲醇溶液和含0.04%（v/v）甲酸与20 mmol/L（v/v）乙酸铵的水溶液为流动相进行梯度洗脱,在加热电喷雾电离（HESI）源、全扫描/实时二级质谱（Full MS/dd-MS²）监测模式下进行检测。结果表明,48种目标化合物在各自范围内线性关系良好,相关系数（r）均≥ 0.9950;检出限为0.1~1.0 μg/kg;平均加标回收率为71.2%~108.8%,相对标准偏差为2.2%~11.8%（n=6）。该法具有操作简单快捷、灵敏度高等优点。     

Evaluation of mycotoxins and their metabolites in human breast milk using liquid chromatography coupled to high resolution mass spectrometry

Humans can be exposed to mycotoxins through the food chain. Mycotoxins are mainly found as contaminants in food and could be subsequently excreted via biological fluids such as urine or human breast milk in native or metabolised form. Since breast milk is usually supposed as the only food for new-borns, the occurrence of mycotoxins in thirty-five human milk samples was evaluated by a newly developed method based on QuEChERS extraction and UHPLC–HRMS detection. The method described here allows the detection of target mycotoxins in order to determine the quality of this initial feeding. The method has been fully validated, with recoveries ranging from 64% to 93% and relative standard deviations (RSD, %) being lower than 20%. Using the method described, non-metabolised mycotoxins such as ZEA, NEO, NIV, ENA, ENA₁, ENB, ENB₁ and metabolites, such as ZEA metabolites, HT-2, DOM and T-2 triol were detected in human milk samples. Results obtained help to estimate the exposure of mothers and infants to mycotoxins. Moreover, to the best of our knowledge, this is the first work describing the simultaneous detection, quantification and screening of mycotoxins and their metabolites in human mature milk.     

Food contaminant analysis at high resolution mass spectrometry: application for the determination of veterinary drugs in milk

Veterinary drugs (VDs) can remain in milk as a consequence of their use in livestock. In order to control the levels of VD residues in milk, screening methodologies can be applied for a rapid discrimination among negative and non-negative samples. In a second stage, non-negative samples are classified as negative or positive samples by using a confirmation method. Pre-target screening methods in low resolution MS (LRMS) are normally applied, but the number of analytes is limited, whereas the information obtained by full scan acquisition in high resolution mass spectrometry (HRMS) is improved. Here, three screening methods (running time<4 min) based on Orbitrap, quadrupole-time of flight (QqTOF) and triple quadrupole (QqQ) have been compared, using in all cases ultra-high performance liquid chromatography (UHPLC). For HRMS, the identification of the VDs was based on retention time (RT) and accurate mass measurements. Confirmation was based on the monitoring of fragments generated without precursor selection. The performance characteristics of the screening method provided reliable information regarding the presence or absence of the compounds below an established value, including uncertainty region and cut-off values. Better results in terms of cut-off values (≤ 5.0 μg kg(-1), except for spiramycin with a cut-off of 13.4 μg kg(-1) for milk samples and 43.1 μg kg(-1) for powdered milk based, emamectin with a cut-off of 42.2 μg kg(-1) for milk samples and doxycycline, with a cut-off value of 15.8 μg kg(-1) in powdered milk-based infant formulae) and uncertainty region were obtained using the Orbitrap-based screening method, which was submitted to further validation and used to analyze different real milk samples. The proposed method can be used in routine analysis, providing reliable results.