固相萃取-高效液相色谱法测定果蔬汁中6种酯类防腐剂

[目的]建立同时检测果蔬汁中对羟基苯甲酸甲酯、对羟基苯甲酸乙酯、对羟基苯甲酸丙酯、对羟基苯甲酸丁酯、对羟基苯甲酸异丙酯、对羟基苯甲酸异丁酯6种酯类防腐剂的固相萃取-高效液相色谱分析方法.[方法]果蔬汁用PEP-SAX-PSA小柱固相萃取,采用Waters XBridge C18色谱柱分离,以0.025mol/L磷酸二氢钠和甲醇为作流动相,梯度洗脱,紫外检测器定.[结果]对样品前处理和色谱分离条件进行了优化.在优化的条件下,6种防腐剂在1.00～50.0 μg/ml范围内的线性良好(相关系数≥0.999 1).对于10 g样品本方法的检出限可达0.025g/kg,相对标准偏差为1.2%～3.1%,加标回收率为80.5%～95.1%.[结论]所采用的固相萃取样品前处理方法简便、准确、有机试剂用量少且提取效率高,方法适用范围广,可用于多种食品中酯类防腐剂含量的测定.     

新显色剂双波长分光光度法同时测定镉与铅

研究新显色剂四（ 对三甲铵苯基） 卟啉（ＴＡＰＰ） 和镉与铅的显色反应,并用双波长分光光度法同时测定镉与铅。在ｐＨ＝ １１ 左右,有溴化十六烷基三甲铵（ＣＴＭＡＢ） 和乙醇的存在下,显色剂和镉与铅形成稳定络合物。由于吸收光谱重叠,选择４３６ｎｍ 为测定波长,４９２ｎｍ 为参比波长进行对镉测定,铅则选择在４６４ｎｍ 波长下进行测定。本方法摩尔吸光系数分别为４－８ ×１０５Ｌ／（ｃｍ ．ｍｏｌ） 、２－７ ×１０５Ｌ／（ｃｍ ．ｍｏｌ） ,线性范围分别为０ ～１－０μｇ／１０ｍｌ、０ ～５－０μｇ／１０ｍｌ。该方法用于人工合成液和陶瓷食具容器浸泡液的测定,加标回收率在８８－１ ％ ～１００－０ ％ ,相对标准偏差在１－０４ ％ ～５－０３ ％ 范围内。     

毛细管气相色谱法测定头发中尼古丁及其代谢产物可的宁

目的建立毛细管气相色谱同时测定头发中尼古丁及其主要代谢产物可的宁的方法。方法头发样品经1.5mol/L NaOH溶液消解,二氯甲烷/甲醇(V/V,3∶1)溶剂萃取,氮气吹干,甲醇定容后直接进样。经SPB-5毛细管柱分离,火焰离子化检测器(FID)检测。结果在优化发样提取和色谱分析条件下,尼古丁和可的宁在4.3ng/mL~1mg/mL和10ng/mL~2mg/mL浓度范围内线性良好(r均为0.9996),方法检出限(S/N=3)分别为4.3ng/mL和10ng/mL。发样中尼古丁和可的宁的加标回收率分别为90.33%~113.1%和92.92%~117.4%,相对标准偏差为2.1%~7.0%和4.4%~8.9%。结论本方法灵敏度高,选择性好,操作简便、快速,易于推广,可用于控烟流行病调查研究批样的检测。     

固相微萃取技术在卫生检验中的应用

本文在简单介绍固相微萃取技术原理，影响因素的基础上，综述了固相微萃取技术在卫生检验中的应用及近年来固相微萃取装置和理论的研究进展，介绍了管内固相微萃取，新型萃取头等最新发展动态。提出目前存在的问题及未来发展展望。     

示波极谱法测定室内空气中的臭氧

示波极谱法测定室内空气中的臭氧黎源倩胡劲梅牟文萱陈浪我们利用臭氧与丁香酚反应生成甲醛，用示波极谱法测定甲醛［１］，从而间接测定室内空气中臭氧的浓度。与比色法相比，本法灵敏度可提高数十倍，抗干扰能力强。方法简便快速，适合于室内空气中臭氧的测定。一、实验...     

顶空固相微萃取-气相色谱法测定环境中挥发性有机物

目的：建立顶容固相微萃取－气相色谱法同时测定环境样品中苯系物，氯代甲烷类等挥发性有机物的方法。方法：采用未涂任何固定液的光纤作为萃取头，自行制作的固相微萃取SPME装置，通过顶空固相微萃取气相色谱法（HS－SPME－GC）测定氯代甲烷和苯系物，并对测定的萃取条件和色谱条件进行了优化，结果：方法的线性范围为二氯甲烷0．14－75．7μg/L,三氯甲烷0．24－84．5μg/L，四氯化碳0．45－137．1μg/L，苯0．03－12．6μg/L，甲苯0．10－24．8μg/L ，乙苯0．06－24．7μg/L，二甲苯0．13－24．8μg/L，相关系数为0．9914－0．9979，检出限为二氯甲烷0．14μg/L,三氯甲烷0．24μg/L ，四氯化碳0．45，苯0．03，甲苯0．10μg/L，乙苯0．06μg/L，二甲苯0．13μg/L，样品加标回收率为80．0％－111．6％，相对标准偏差为4．4％－8．1％，结论：该法简便，快速，灵敏度高，重现性好，分析成本低。     

酒中醇,醛,酯的气相色谱分析

The determination of alcohols, aldehydes and esters in potable spirits was accomplished with a new kind of chromatographic packing made in China--graphitized carbon black (SHT2), modified with PEG-20M. By means of programmed temperature and direct injection, quantitative measurements of 22 components in potable spirits can be simultaneously finished in 50 min. The detect limit of the method was 1 ppm. The coefficients of variation were less than 10%. The recovery tests of 11 components were carried out and the recoveries were in the range of 81.0-106.8%. The method can be applied not only to hygienic monitoring of methanol, fusel oil and furfural, but also to quantitative monitoring of aromatic components in potable spirits. The measurements of several Sichuan spirits samples were made with satisfactory results.     

尿铬测定方法研究

Systemic investigations of chromium determination in urine with diphenylcarbazide were carried out and suitable analytic conditions for the determination established. Urine samples were first digested with nitric acid-hydrogen peroxide and then the chromium in the sample was oxidized to the hexavalent state by permanganate in acidic medium. After the excess oxidizing reagent was destroyed with sodium nitrite, chromium (VI) combined with diphenylcarbazide, forming a stable red color. The average recovery was 101.1%, ranging from 82.0% to 115.8%. Coefficients of variation were in the range from 2.0% to 8.4%. The method can be conveniently applied to the analysis of trace chromium in urine samples with satisfactory sensitivity and recovery. The method was applied to the measurement of 180 normal and 124 CHD (coronary heart disease) urine samples from Chengdu city. The mean of chromium level in normal urine was 6.1 micrograms/L and the range with 95% confidence of urine chromium was determined as 1.7-11 micrograms/L. The mean of chromium level in CHD urine samples was 4.2 micrograms/L. By statistical analysis, there was a significant difference between the means of the two groups (t' = 6.9, P less than 0.05).     

示波极谱法测定血中铅的方法研究

作者报道了在盐酸－碘化钾－钒（ＩＶ）－乙醇－抗坏血酸体系中，用络合催化极谱法测定血中微量铅的方法。在此体系中，铅的峰电位为－０．５４Ｖ（ＶＳ．ＳＣＥ），铅浓度在０～１．００μｇ／３ｍｌ范围内与峰电流有良好的线性关系。样品加标回收率为７６．０％～１０５．０％，平均回收率为９１．０％。相对标准偏差为３．６％～７．０％。最低检测浓度为４５μｇ／Ｌ。采用本法对２４例正常人和６例铅作业工人血中铅的测定，结果与临床诊断符合。该法操作简便快速、灵敏度高、结果准确可靠，适合于正常人和铅作业工人血铅的测定。     

流动注射—二极管阵列检测分光光度法同时测定食品中的硫胺素和核黄素

建立了流动注射同时测定食品中硫胺素（VB1）和核黄素（VB2）的简单快速的方法。在氢氧化钠和碳酸氢钠混合溶液的缓冲介质中,以对氨基苯磺酸重氮盐与硫胺素发生偶氮反应,核黄素不发生反应,采用电感耦合器件二极管阵列检测装置进行检测,实现了对食品中VB1、VB2的同时测定。方法的线性范围VB1和VB2分别为0.0066mg/ml和0.0084。平均加标回收率VB1和87.3％～105.4％,VB2o 90.0％～99.7％;相对标准偏差VB1为3.6％～7.0％/VB2为4.7～6.6％。方法简单、快速、测定干扰小,结果与标准测定方法一致。