Occurrence of aflatoxin M1 in milk samples from Italy analysed by online-SPE UHPLC-MS/MS

The occurrence of aflatoxin M1 in 69 milk samples collected in a south region of Italy in 2016 was evaluated. The samples were analysed using an automated method based on online SPE coupled with UHPLC tandem mass spectrometry. After a salt induced liquid–liquid extraction with acetonitrile to remove protein from milk, the extract was diluted with water and analysed using an automated online SPE MS/MS method. Among the analysed samples no one had AFM1 higher than the legally allowable limits whereas 71.4% of the other analysed samples were above the LOD of the method. The highest contamination level of AFM1 was found in pasteurised milk (44.39 ng kg^?1). The results show the worrying and widespread of AFM1 contamination, highlighting the necessity of monitoring studies in order to evaluate the reduction of the maximum legal limit.     

Simultaneous Determination of Palladium, Platinum and Rhodium by On-Line Column Enrichment and HPLC with 4-Hydroxy-1-Naphthalthiorhodanine as Pre-Column Derivatization Reagents

In this paper, 4-hydroxy-1-naphthalthiorhodanine (HNTR) was synthesized, and a new method for the simultaneous determination of palladium, platinum and rhodium ions as metal-HNTR chelates was developed using rapid column high-performance liquid chromatography combined with on-line enrichment. The palladium, platinum and rhodium ions were pre-column derivatized with HNTR to form colored chelates. The Pb-HNTR, Pt-HNTR and Rh-HNTR chelates could be absorbed onto the front of the enrichment column when they were injected into the injector and sent to the enrichment column [ZORBAX Stable Bound, 4.6 × 10 mm, 1.8 μm] with a buffer solution of 0.05 mol L⁻¹ sodium acetate-acetic acid (pH 4.0) as mobile phase. After enrichment, and by switching the six-ports switching valve, the retained chelates were back-flushed by mobile phase and traveling towards the analytical column. Separation of these chelates on the analytical column [ZORBAX Stable Bound, 4.6 × 50 mm, 1.8 μm] was satisfactory with 68% acetonitrile (containing 0.05 mol L⁻¹ of pH 4.0 sodium acetate-acetic acid buffer salt and 0.1% of tritonX-100) as mobile phase. Palladium, platinum and rhodium were separated completely within 2 min. The detection limits (S/N = 3) of palladium, platinum and rhodium are 1.2 ng L⁻¹, 1.5 ng L⁻¹ and 1.8 ng L⁻¹, respectively. This method was applied to the determination of palladium, platinum and rhodium in water, urine and soil samples with good results.     

Kinetic On-line Evaluation of Chemical Reactions

A computer program was developed for kinetic evaluations of calorimetric experiments to predict the further reaction run under adiabatic conditions. Kinetic modeling is based on elementary reaction steps whose rate laws form a set of differential equations. For the continuous parameter optimization time-temperature data and their derivatives are used. A special calorimeter of the ACTRON series with safety equipment was applied to investigate the kinetics of chemical reactions and to test kinetic on-line evaluations. In the paper, examples for the reaction of n-propanol with o-chlornitrobenzene and for the alcoholysis of phenyl isocyanate are given.This revised version was published online in November 2005 with corrections to the Cover Date.     

在线富集-HPLC法测定水溶液中多环芳烃

本文采用在线富集-HPLC 法测定水溶液中多环芳烃。先使样品中的组分浓缩在一支短的富集柱上,然后切换阀门,将富集物洗脱到 RPHPLC 的体系中进行分离,并用紫外和荧光检定器对冼脱物进行检测。为了提高检测灵敏度和选择性,实验中采用了荧光波长程序技术。考察了富集的最佳条件,并比较了在线法与离线法的测定结果。     

流动注射在线过滤稀释原子吸收法测定药物制剂中卡托普利

提出了卡托普利的FI-AAS分析新方法。它是基于在适当酸度条件下卡托普利将Cu^2 还原为Cu^ ，新生的Cu^ 与SCN^-生成白色沉淀，经流动注射在线过滤稀释，以AAS法测定反应剩余Cu^2 的量来间接测定卡托普利的量。在2～100mg/L范围内呈良好的线性关系，回收率为97.1%～99.5%，采样频率为100h^-1。方法简单、快速、选择性好，节省试剂，用于卡托普利的测定，获得满意结果。     

重质石油中含氮化合物的形态及分布分析──高效液相色谱－气相色谱在线联用分析方法研究

研究了高效液相色谱－气相色谱（ＨＰＬＣ－ＧＣ）联用技术及其应用。采用正相微柱ＨＰＬＣ－ＧＣ联用及完全溶剂蒸发方式，分析了煤焦油馏分──蒽油，显示了微柱ＨＰＬＣ－ＧＣ联用的应用潜力。采用正相ＨＰＬＣ－ＧＣ联用结合反冲技术，分离了重质石油中的饱和烃、芳烃和极性化合物（含氮化合物等）。     

Electrochemical On‐line ICP‐MS in Electrocatalysis Research

Electrocatalyst degradation due to dissolution is one of the major challenges in electrochemical energy conversion technologies such as fuel cells and electrolysers. While tendencies towards dissolution can be grasped considering available thermodynamic data, the kinetics of material's stability in real conditions is still difficult to predict and have to be measured experimentally, ideally in‐situ and/or on‐line. On‐line inductively coupled plasma mass spectrometry (ICP‐MS) is a technique developed recently to address exactly this issue. It allows time‐ and potential‐resolved analysis of dissolution products in the electrolyte during the reaction under dynamic conditions. In this work, applications of on‐line ICP‐MS techniques in studies embracing dissolution of catalysts for oxygen reduction (ORR) and evolution (OER) as well as hydrogen oxidation (HOR) and evolution (HER) reactions are reviewed.     

尿碘的流动在线消化催化光度法测定

将尿样消化引入ＦＩＡ流路，并与催化光度法相结合，建立了尿碘的流动在线消化催化光度法，从而实现了尿碘的快速自动测定。本法分析速度１３０／ｈ，检测范围宽达４０～１６００μｇ／ＬＩ＾－，重现性好，实际尿样测定ＲＳＤ≤６．９％（ｎ＝８），方法具有创新和实用性，对尿碘的快速准确定值及碘缺乏病的防治有重要意义。     

在线计算中的几个未解问题(英文)

讨论组合优化中的一个迅速发展的领域──在线计算，选出几个典型的未解问题进行方法介绍．     

具有智能评阅功能的在线有机化学习题平台:ACE: Organic简介及其在教学中的应用*

ACE: Organic(Achieving Chemistry Excellence: Organic Chemistry)是具有智能反馈功能的在线有机化学习题平台。学生利用系统中的画图软件在线完成每个练习题后,平台会判断学生的回答是否正确,即时给出评价与提示,引导学生找到解决问题的思路。对于复杂的机理与合成题,ACE可以接受多种合理的回答。教师可以通过查看平台的统计数据,随时了解学生对知识点的掌握情况。ACE设有论坛,便于教师和学生互动。教学实践证明,ACE的开放有效地提高了学生对有机化学的学习兴趣,培养了学生严谨的科学态度。