超高效液相色谱电喷雾串联四极杆质谱法检测豆制品中12种禁用工业染料

建立了超高效液相色谱-电喷雾串联四极杆质谱(UPLC-MS/MS)同时检测豆制品中12种橙黄色工业染料(碱性橙2、碱性橙21、碱性橙22、苏丹黄、苏丹橙G、二乙基黄、碱性嫩黄O、溶剂黄124、酸性橙Ⅱ、酸性间胺黄、酸性黄11和茜素黄R)的分析方法。样品经酸化乙腈提取;提取液于-20℃冷冻2 h后离心,可有效去除豆制品中的脂质类干扰物;梯度洗脱条件下经ACQUITY UPLCBEH C18柱(1.7μm,2.1 mm×100 mm)分离后采用多离子反应监测模式(MRM)检测,4种工业染料(酸性橙Ⅱ、酸性间胺黄、酸性黄11和茜素黄R)使用负离子模式,以乙腈-0.1%氨水为流动相,其余8种采用正离子模式检测,流动相为乙腈-0.1%甲酸水。结果表明:豆制品中12种工业染料的定量下限(LOQ)为0.2~10.0μg/kg,3个加标水平的回收率为76.2%~122.0%,相对标准偏差为1.1%~7.4%,各项指标满足食品中痕量污染物检测的需要。该方法操作简便、灵敏度高,实现了12种禁用橙黄色染料的同时提取和净化,适合于豆制品中非法添加工业染料的筛查、确证。     

Extraction with Acidified Methanol—An Easy and Effective Method of Methyl Chlorogenate Formation,as Studied by ESI-MS

Among the different Hawthorn species, Crataegus monogyna seems to be one of the most often used in herbal medicine, and is commercially available. The methanolic extract and the acidified methanol extract of an herbal medicinal product based on Crataegus monogyna inflorescences were analyzed by using high-pressure liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS). On the basis of m/z of [M-H]⁻ ions and characteristic fragmentation patterns, a number of polyphenolic compounds, namely flavonoids and chlorogenic acids, were identified. It was found that the contents of the acid extract were enriched with methyl chlorogenates showing attractive biochemical properties. Analogous results were obtained for other plant materials, e.g., nectarine kernels. Apart from that, acid extraction had a minor influence on the polyphenolic compounds present in the plants, and thus it did not affect the natural antioxidant values of the plant extracts.     

Influence of O/S/Se Exchange on the Stability of 1,3,4-Selana(Thia/Oxa)Diazole-Palladium Complexes as Studied by Electrospray Ionization Mass Spectrometry

Abstract

The complexes of 2-phenyl-1,3,4-selena(thia/oxa)diazole with a palladium cation were studied by using electrospray ionization mass spectrometry. Palladium chloride was used as a source of palladium cations. The complexes of ligand:metal stoichiometry of 3:1 (ions [L₃+PdCl]⁺) were formed for selenadiazoles and thiadiazoles. Quantum mechanical calculations performed indicated that ligand molecules are attached to palladium cation by the N-4 atom. The fragment ions formed [L₂–H+Pd]⁺ may be regarded as organometallic species. Selenadiazoles were found more prone to form the palladium complexes than thiadiazoles. Oxadiazoles did not yield the respective palladium complexes. For comparison, the nickel cation was also included in the study but only 1:1, and less abundant 2:1 complexes were observed. Exchange of selenium into oxygen does not affect the abilities of the ligands to form nickel complexes.     

高效液相色谱-四极杆/静电场轨道阱高分辨率质谱检测酱油中的4-甲基咪唑与2-甲基咪唑

建立了高效液相色谱-四极杆/静电场轨道阱高分辨率质谱测定酱油中4-甲基咪唑(4-MI)和2-甲基咪唑(2-MI)的方法。酱油样品经水稀释,过MCX固相萃取小柱,经5%的氨化甲醇洗脱后,于45℃下氮气吹干,用乙腈水溶液溶解残渣,涡旋充分混合后过0.45μm滤膜。采用Agilent HILIC Plus(2.1 mm×100 mm,3.5μm)色谱柱进行分离,以乙腈-5.0 mmol/L乙酸铵(80∶20)为流动相进行等度洗脱。质谱采用正离子模式,在质荷比(m/z)50~100范围内通过高分辨质谱全扫描模式提取目标化合物的精确质量数,以一级母离子为定量离子,外标法定量。在所建立的色谱条件下,4-MI和2-MI能够得到较好的分离。该方法对4-MI和2-MI的检出限可达2.5 mg/kg。在25~500 ng/m L浓度范围内线性关系良好,相关系数均大于0.99。对生抽、老抽、黄豆酱油及有机酱油中4-MI和2-MI进行3个水平的加标实验,平均回收率为78.3%~95.7%,相对标准偏差(RSD)不大于9.4%。该方法样品处理过程简单,适用于酱油中4-MI和2-MI的测定,对规范酱油生产和焦糖色素的加入具有重要意义。     

气相色谱-质谱方法快速测定馏分油累积收率和性质

采用GC/MS与偏最小二乘法结合的方法测定了汽油馏分、柴油馏分、润滑油馏分、VGO馏分及渣油馏分的累积收率以及汽油馏分、柴油馏分的相对密度,建立了采用MS数据预测这5种馏分油累积收率和汽油馏分、柴油馏分相对密度的PLS校正模型。验证集结果表明：GC／MS方法与标准方法测定的结果之间无显著性差别。用GC／MS方法可以实现馏分油累积收率及性质的快速测定,与标准方法相比,大大缩短了分析时间。     

固相萃取-气相色谱/负化学电离-质谱法测定酸水解植物蛋白及酱油中的3-氯-1,2-丙二醇

建立了酸水解植物蛋白及酱油中3-氯-1,2-丙二醇(3-MCPD)的固相萃取-气相色谱/质谱测定方法。样品经Aoisa-HBL固相萃取柱萃取,正己烷-乙酸乙酯净化提取,七氟丁酰咪唑衍生,衍生物经气相色谱/负化学电离-质谱（GC/NCI-MS）选择离子模式(SIM)检测,外标法定量。3-MCPD的定量检测限为0.5 μg/kg,平均回收率为92.2%～97.4%,相对标准偏差为3.6%～10.9%。该方法检测灵敏度高,定性定量准确。