山莨菪碱及其大鼠肠内菌体外代谢物的液相色谱-质谱法分析

目的 用液相色谱-电喷雾离子阱串联质谱联用法研究山莨菪碱在大鼠肠内菌中的代谢.方法 以山莨菪碱优化色谱及质谱条件,总结其色谱及质谱行为规律.将山莨菪碱与大鼠肠内菌体外厌氧温孵培养,并与空白样品及山莨菪碱对照品进行比较,依据被测物的多级质谱数据,鉴定代谢物并阐述其结构.结果 在温孵液中发现了山莨菪碱的脱水及水解代谢产物,即脱水山莨菪碱、6β-羟基托品和托品酸.结论 该方法灵敏、快速、简单,适合于药物代谢分析.     

基于标准提取物的欧洲越橘提取物质量控制方法及药效活性关联研究

目的 建立对照品非依赖性的20种花青素类成分定量分析方法,并利用该法对市售欧洲越橘Vaccinium myrtillus提取物进行质量控制,同时筛选出代表性抗氧化活性成分。方法 以欧洲越橘标准对照提取物替代对照品,采用超高效液相色谱-三重四极杆串联质谱（UPLC-QQQ-MS/MS）联用技术,建立一种针对20种花青素类成分的定量方法,并利用该法对10批市售欧洲越橘提取物中的花青素类成分含量进行研究。采用DPPH自由基清除法和总抗氧化能力测试法评价不同欧洲越橘提取物的抗氧化能力。结果 方法学验证结果显示,20种花青素类成分线性良好,r为0.999 4～1.000 0,精密度RSD为0.05%～4.23%,稳定性RSD为0.29%～3.38%,平均加样回收率为98.1%～102.1%,RSD为0.50%～4.12%。样品分析结果显示,不同样品中部分花青素类成分含量存在显著差异,其中锦葵素变化最大,RSD为18.23%。欧洲越橘提取物具有较好的DPPH自由基清除能力和总抗氧化能力。其中矢车菊素与DPPH自由基率相关性为0.94,芍药素-3-O-半乳糖苷与总抗氧化活性相关性为0.93。二者有望...     

黄精炮制品多糖多元指纹图谱的建立及化学模式识别

目的 构建黄精炮制品多糖的酶水解产物指纹图谱,结合化学计量学方法评价不同蒸晒次数黄精炮制品多糖的差异。方法 采用糖苷酶水解,结合高效薄层色谱（high thin-layer chromatography,HPTLC）、亲水作用色谱-高效液相色谱-蒸发光检测器（hydrophilic interaction liquid chromatography-high performance liquid chromatography-evaporative light scattering detector,HILIC-HPLC-ELSD）和超高效液相色谱-四级杆飞行时间串联质谱（ultra high pressure liquid chromatography-quadrupole time of flight tandem mass spectrometry,UHPLC-QTOF/MS）对相应的酶解产物进行高效分离和检测。由此产生的自下而上的指纹图谱反映了黄精炮制品多糖的变化,通过相似度和偏最小二乘-判别分析（partial least squares-discriminant analysis,PLS-DA）对指纹图谱进行综合评价。结果 HPTLC分析发现,果糖随着蒸晒次数的增加逐渐降低,结合色谱分析发现,六蒸六晒和十二蒸十二晒为黄精炮制过程中的转折点。同时根据酶水解中寡糖的变化,利用相似度和PLS-DA对不同蒸晒次数的黄精炮制品进行了清晰的聚类。结合UHPLC-QTOF/MS分析表明,不同蒸晒次数黄精炮制品中含有蔗糖、蔗果三糖、蔗果四糖、蔗果五糖、蔗果六糖、蔗果七糖及蔗果八糖。结论 基于酶解法分析不同蒸晒次数样品的质量动态变化,结合所建立的多元指纹图谱,进一步阐释了不同蒸晒次数黄精炮制品的科学内涵。     

Regulated Mycotoxin Occurrence and Co-Occurrence in Croatian Cereals

A total of 209 samples of various cereal crops (maize, wheat, barley, rye and oats) grown in Croatian fields during 2016 and 2017 were collected to analyze and determine the occurrence and co-occurrence of EU regulated mycotoxins in cereals (AFB1, AFB2, AFG1, AFG2, DON, FB1, FB2, ZEA, T-2, HT-2 and OTA). The analysis, performed by a validated confirmatory LC-MS/MS method based on a dilute and shoot principle, highlighted Fusarium mycotoxins as the main contaminants, often co-occurring in samples from both years (50.0% in 2016 and 33.7% in 2017). DON was found to be the most frequent mycotoxin, present in 72.5% of the 2016 samples and 32.6% of the 2017 samples, while maize proved to be the most contaminated cereal type of both years with FUM as the most abundant mycotoxins, with an average concentration of 1180 µg/kg. Moderate temperatures with periods of high humidity favored the accumulation of DON in wheat samples instead of other Fusarium mycotoxins, while similar conditions favored maize contamination with FUM. A total of 8.3% of all the 2016 harvest samples and 7.9% of the 2017 harvest samples were assessed as non-compliant, containing mycotoxins in concentrations higher than the levels set by the EU legislation for food.     

A simple and reliable bile acid assay in human serum by LC‐MS/MS

BackgroundBile acids, as important signaling molecules and regulatory factors acting on glucose, lipid, and energy metabolism, are always involved in liver, biliary, and intestinal diseases. Development and validation of a simple liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method for determination of bile acids is significant for the routine clinical testing.MethodsFifty microlitre of serum was mixed with 10 μl of the internal standard working solution and then 140 μl of methanol for protein precipitation. After centrifuged, the supernatant was directly used for LC‐MS/MS analysis.ResultsGood separation of all bile acid species was achieved. The method was validated with consistent linearity for individual bile acids, good recovery, low carryover, satisfactory sample stability, and analytical specificity against hemolysis, lipemia, and bilirubinemia. The intra‐day and the inter‐day imprecision values were in the range of 1.53%–10.63% and 3.01%–13.98%, respectively. No obvious matrix effect was observed. The reference intervals of bile acids in adults have been established for the clinical testing.ConclusionsThe low sample volume, simple sample preparation, good separation of all species, and satisfying validation results make this LC‐MS/MS approach suitable for usage as a high‐throughput assay in routine clinical laboratories.