微量进样火焰原子吸收法测定高血脂患者血清中Ca,Mg,Cu含量及其统计分析

为降低血清用量,设计了简单的连续微量进样装置,每次进样量可准确控制在250～300μL,即提高试液利用率6～8倍。用微量进样原子吸收法对混合血清中Ca,Mg,Cu的含量进行了重复测定,求出测定的相对标准偏差分别为:4.5%(Ca),3.2%(Mg),5.8%(Cu),可完全满足测定要求。用此方法测定了无其他疾病单纯高血脂患者和正常人血清中Ca,Mg,Cu的含量,并用u检验,Kruskal and Wallis法及扩大的t检验对测定数据进行了统计分析,结果表明,高血脂患者与正常人对比,血清中Ca含量无差别;Mg含量较高;Cu含量较低,且TG值越高,血清Cu含量越低。此结果可为医学科研和临床提供参考。     

乳酸脱氢酶反应器用于流动注射分析测定人体液中的L-乳酸

本文用[3-(2-氨乙基)氨丙基]三乙氧基硅烷试剂胺化一定孔径大小的载体,用戊二醛作偶联剂,将乳酸脱氢酶固定于其上,装入柱内,联结于流动体系中。L-乳酸的浓度在0.1～4.4mmol/L呈线性,检测限为0.4nmol(s/N=4),相对标准偏差≤1.2％,回收率在96％～103％。每小时进样35次。测定了固定化LDH的表观米氏常数及人血清和尿中的L-乳酸。     

动力学—两次标准加入法同时测定钼和钨

本文提出了动力学－两次标准加入法双组份同时测定的新方法，讨论了测定的基本原理；用停流ＦＩＡ光度法研究了钼和钨共同催化的Ｈ２Ｏ２－Ｉ＾－动力学反应体系，并建立了钼和钨同时测定的条件，用本法测定了钢样和模拟样品中的钼、钨含量，结果满意，钼和钨的回收率分别为９７％－１０２．６％和９８．２％－１０３％；相对标准偏差分别为２．８％－３．２％和２．１％－３．５％。     

流动注射光度法测定肉制品中的亚硝酸盐

流动注射光度法测定肉制品中的亚硝酸盐许汉英＊赵志明梁春王宝东（吉林进出口商品检验局长春１３００６２）关键词肉制品，亚硝酸盐，ＦＩ－分光光度法１９９６－１１－２８收稿，１９９７－０５－２２修回食品及环境样品中亚硝酸盐的测定有分光光度法［１～３］，极谱法...     

直接进样电喷雾质谱分析烷基苯磺酸盐

采用直接进样法，电喷雾质谱分析三次采油用烷基苯磺酸盐，可以得到定性结果，定出该表面活性剂中各组分的分子式，操作简单易行．     

RIM聚氨酯脲的微相分离的DSC研究──硬段结构和含量对微相分离的影响

用ＤＳＣ法研究了二乙基甲苯二胺和４，４＇－氨基二苯基甲烷（ＭＤＡ）扩链的硬段含量为２７％～６０％的两个系列的反应注射成型（ＲＩＭ）聚氨酯脲（ＰＵＵ）弹性体的微相分离。聚合反应动力学对ＲＩＭＰＵＵ的微相分离有很大影响．随着硬段浓度的增加微相分离程度下降，ＭＤＡ扩链系列聚合总反应速度快，微相分离驱动力弱，在硬段生成反应比软段生成反应快的条件下，该系列的微相分离程度较低。聚合总反应快，且硬段间氢键化作用很强的性质造成ＲＩＭＰＵＵ非平衡的形态。聚合总反应速度的增加相当于微相分离驱动力的下降。     

Validation of two analytical methods for the determination of ochratoxin A by reversed-phased high-performance liquid chromatography coupled to fluorescence detection in musts and sweet wines from Andalusia

Some Spanish sweet wines are made from raisins, grapes dried by direct exposure to the sun after picking. This drying process can encourage ochratoxin A (OTA) formation. OTA is a mycotoxin formed by several fungi. It has been linked to nephropathy in humans, and may have a long half-life in humans. The aim of this study is to develop and to apply two procedures for the analysis of OTA in grape musts (during the raisining process) and sweet wines, respectively. Reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to fluorescence detection (FLD) was employed in both analytical methods. In grape must, the method involves the direct injection of the sample in a HPLC-FLD system without any kind of prior clean-up procedure. The complexity of the sweet wine samples requires a solid-phase extraction (SPE) clean-up on a C18 column which enables the OTA to be isolated from the matrix. The methods used were statistically validated. The validation also included the comparison of the slopes of the curve obtained with standards and the regression curves obtained by the addition of a standard. Two different studies of standard additions were conducted. One method was validated without sample preparation and it was applied to must samples. The other method was validated with SPE extraction and it was applied to sweet wine samples. Recovery was always better than 89.69%. The limit of detection (S/N = 3) and limit of quantification (S/N = 10) were established at 0.22 and 0.77 μg l⁻¹, respectively. In general, the analytical data obtained provided good results at the sub-μg l⁻¹ concentration level.     

程序升温汽化大体积进样气相色谱法同时测定空气中的甲醛及其他10种羰基污染物（英文）

Long-term indoor-air limit for formaldehyde stipulated by the European Commission is 1 μg/m3,while the World Health Organization has set a threshold of 100 μg/m3 that should not be exceeded for more than 30 min. To date,however,only a few analytical techniques have been developed that can be used to detect formaldehyde at these very restrictive limits. Thus,there is a need to develop for comprehensive methods for analyzing airborne formaldehyde and other carbonyl pollutants in the ambient environment. The aim of this study is to develop a highly sensitive online automated preconcentration gas chromatographic method using large-volume injection with a programmed temperature vaporization injector for the analysis of airborne formaldehyde and ten other carbonyl compounds. The influence of several parameters,such as the maximum volume injected,programmed temperature vaporization transfer time and temperature,carrier gas flow rate,and type of packing material was investigated. After optimization,highly satisfactory results in terms of the absolute and methodological detection limits were achieved,i. e. as low as the μg/m3 level for all the carbonyl pollutants studied. A commercially available sampler,originally designed for active sampling,was evaluated as a passive sampling device;this optimized technique was applied to monitor the concentrations of carbonyl pollutants in the indoor air of ten public buildings in Florence. The strength of this methodology lies both in the low detection limits reached in the simultaneous analysis of a wide group of 2,4-dinitrophenylhydrazine derivatives,and the potential adaptability of this method to other gas chromatographic applications to achieve lower sensitivity.     

Dispersive micro‐solid‐phase extraction combined with online preconcentration by capillary electrophoresis for the determination of glycopyrrolate stereoisomers in rat plasma

A simple and sensitive analytical method for four isomers of glycopyrrolate in rat plasma was developed using cation‐selective exhaustive injection‐sweeping cyclodextrin‐modified electrokinetic chromatography (CSEI‐Sweeping‐CDEKC) for online enrichment combined with dispersive micro‐solid‐phase extraction pretreatment. The CSEI‐Sweeping‐CDEKC was conducted on an uncoated fused silica capillary (40.2 cm × 75 μm) with an applied voltage of –20 kV. The electrophoretic analysis was carried out in 30 mM phosphate solution at pH 2.0 containing 20 mg/mL sulfated‐β‐cyclodextrin and 5% acetonitrile. Under these optimized conditions, the detection limit for racemic glycopyrrolate was found to be 2.0 ng/mL and this method could increase 495‐fold detection sensitivity compared with the traditional injection method. Additionally, the parameters that affected the extraction efficiency of dispersive micro‐solid‐phase extraction were also examined systematically. The glycopyrrolate isomers in rat plasma samples as low as 0.0625 μg/mL were able to be separated and detected by capillary electrophoresis with the aid of CSEI‐sweeping. The findings of this study show that the dispersive micro‐solid‐phase extraction pretreatment coupled with CSEI‐Sweeping‐CDEKC is a rapid and convenient method for analyzing glycopyrrolate isomers in rat plasma.