十六烷基三甲基溴化铵存在下锑膜修饰玻碳电极差分脉冲溶出伏安法测定尿中痕量铅、镉

目的考察并优化同位镀锑膜修饰玻碳电极同时测定Pb2+、Cd2+的方法。方法采用十六烷基三甲基溴化铵(CTAB)作为增敏剂,以锑膜修饰玻碳电极作为工作电极差分脉冲溶出伏安法测定尿中痕量Pb2+、Cd2+。结果 Pb2+、Cd2+在锑膜电极上可得到灵敏的溶出峰,溶出电位分别为-0.48 V和-0.73 V。当富集时间为180 s时,Pb2+、Cd2+的线性范围为0~100μg/L(r≥0.991),检出限分别为0.47μg/L和0.78μg/L,Pb2+、Cd2+的加标回收率分别为92.0%~104.3%和94.0%~102.6%,相对标准偏差(RSD)分别为4.1%~5.0%和2.8%~6.1%。利用该方法测定了尿样中Pb的含量,结果令人满意。结论该方法灵敏度高,精密度、准确性好,锑膜修饰玻碳电极可作为一种新的环保膜电极代替汞膜电极用于尿样中Pb含量的检测。     

锑膜修饰电极差分脉冲溶出伏安法测定痕量锡

目的:建立一种新的快速检测方法测定实际样品中的Sn。方法:采用同位镀锑膜玻碳电极,利用差分脉冲溶出伏安法对痕量Sn进行测定。结果:优化实验条件下,相关性好(r>0.99),测得Sn2+的线性范围和最低检出限分别为10~120μg/L和0.50μg/L,样品加标回收率为96%~98%。结论:锑膜电极可成为继铋膜电极之后又一种新的环保型膜电极,用于实际样品中重金属的检测。     

溶出伏安法与计算机差谱技术联合测定尿中铅、锌、铜、镉

介绍用阳极溶出伏安法测定尿中铅、锌、铜、镉时 ,用计算机差谱技术 变时溶出示差功能消除背景电流对溶出信号的干扰。尿样不消化 ,测定时不需除氧。     

纳米金/铋膜修饰电极示差脉冲溶出伏安法检测痕量铅

目的建立纳米金/铋膜修饰玻碳电极检测痕量铅的方法。方法运用电化学沉积法和同位镀铋法构建纳米金/铋膜修饰电极,采用示差脉冲溶出伏安法测定水中铅离子的浓度。结果考察了缓冲液pH值、富集电位、富集时间及镀铋溶液浓度对溶出峰的影响,并在最优的实验条件下,对1~14μg/L范围内的Pb~(2+)进行了定量测定,发现Pb2+浓度和峰电流具有较好的线性关系,且线性方程为I(A)=1.649×10~(-7)+2.675×10~(-7) C(μg/L)(r2=0.999),检出限为0.53μg/L(S/N=3)。结论该方法简便快捷,灵敏度较高,结果准确,重现性良好,可实现水中痕量铅的快速测定。     

乳化剂OP增敏微分电位溶出法同时测定食品中铅铜的研究

筛选出以非离子表面活性剂乳化剂（ＯＰ）聚乙二醇辛基苯基醚为增敏剂，在０．３ｍｏｌ／ＬＨＣｌ介质中微分电位溶出法同时测食品中痕量铅、铜。用同位镀汞样品标准加入法直接测定饮料、发酵酒、调味品等中的铅及铜，回收率为９５％～１０５％，ＲＳＤ为０．８％～７．９％。本法用于实际样品分析结果与国标法一致。     

微波消解同时测定农产品中铅、镉、汞

目的:建立一种适合同时测定农产品中铅,汞,镉的样品前处理方法。方法:采用微波消解方法处理样品,样品消化液经赶酸后定容,分别用来测定汞和铅、镉。结果:测定铅,镉,汞方法的线性范围分别为:0.0μg/L～20μg/L,0.0μg/L～2μg/L,0.0μg/L～5μg/L;相关系数分别为:0.9979,0.9978,0.9988;回收率分别为:95.8%～103%,95.1%～104%,98.4%～110.6%;方法的检测限分别为0.012μg/L,0.009μg/L,0.0027μg/L。结论:该方法精密度好,准确度高,快速简单,能够很好地满足农产品中铅,汞,镉含量的测定要求。     

溶出伏安法测定人发中钴和镍

由于钴和镍在汞中的溶解度较小,所以无法用一般极谱法进行测定。经研究发现钴和镍与丁二酮肟生成的络合物可被悬汞电极所吸附,通过吸附可将钴和镍预富集于电极上,然后向阴极方向进行电位扫描,即可得到钴和镍的溶出峰。实验表明,峰电流大小与钴和镍的浓度在1 60ng/ml范围内成线性。方法的检出下限为1ng/ml,方法的相对标准偏差小于3.5％,样品加标回收率为99 104％。     

同位镀锑膜修饰电极方波溶出伏安法同时测定痕量锡、镉

目的:建立同位镀锑膜电极测定痕量锡和镉的新方法。方法:在玻碳电极上,采用同位镀锑的方法富集被测离子并形成锑膜,利用方波脉冲伏安法使富集的Sn、Cd重新溶出,根据溶出峰电流,实现对痕量Sn2+、Cd2+的同时测定。在十六烷基三甲基溴化胺(CTAB)存在的条件下,溶出峰形良好。讨论了底液的pH值、CTAB浓度、富集时间、富集电位和不同的扫描速率对金属离子溶出峰的影响。结果:在优化实验条件下,Sn2+和Cd2+的线性范围分别为5μg/L～180μg/L和10μg/L～170μg/L,最低检出限分别为0.46μg/L和2μg/L。利用本方法测定了茶叶中Sn2+的含量,结果令人满意。结论:锑膜电极可成为又一种新的环保型膜电极用于重金属离子的测定。     

nano-TiO2修饰玻碳电极微分脉冲阳极溶出伏安法测定全血中砷含量

目的:建立一种电化学测定全血中砷的方法。方法:采用微波消解法处理全血样品,在优化测定条件下以微分脉冲阳极溶出伏安法测定砷的含量。结果:砷的检出限为0.37μg/L;砷标准溶液在1.0μg/L~15.0μg/L范围内线性良好,相关系数为0.998;测定含5.0μg/L As标准溶液的相对标准偏差为2.0%。样品加标回收率为95%~97%。结论:该方法灵敏度、准确度高;操作方便快速;具有较低的检出限,能满足测定全血中砷含量的检测工作。     

Improved method for the determination of urinary delta-aminolevulinic acid in lead workers

An improved method for the determination of urinary delta-aminolevulinic acid (ALA) as an indicator of lead absorption is described. It is a modification of the analytical procedure described by Tomokuni and Ogata in 1972. In the present method, the spot urine from lead-exposed workers which was diluted 3-fold with distilled water beforehand was used as the sample to eliminate as much as possible the urinary matrix interference. In addition, methyl acetoacetate was used as the condensation reagent for ALA-pyrrole, because the color intensity of ALA-pyrrole was higher with the use of methyl acetoacetate than that with ethyl acetoacetate which was used in the original method. The urinary ALA value determined by the present method was similar to that measured using an internal-standard addition method. This method is suitable as a rapid and inexpensive screening procedure for the routine quantitative analysis of urinary ALA.     

Distribution of blood lead, blood cadmium, urinary cadmium, and urinary arsenic levels in employees of a copper smelter

A cross-sectional medical examination of a copper smelter work force included determination of blood lead (Pb-B), zinc protoporphyrin (ZPP), blood cadmium (Cd-B), urinary cadmium (Cd-U), and urinary arsenic (As-U), since it was known that such metal impurities were present in the copper concentrate. A total of 776 copper smelter employees (680 active and 96 retirees and ex-employees) were examined. Another 144 men, never employed in the smelter, but who had worked in copper mines (and sometimes in gold mines) were also examined. Mean Pb-B, ZPP, Cd-B, and As-U were significantly higher in active copper smelter employees than in retirees or miners, indicating exposure and absorption in the copper smelter. Significant correlations between Pb-B and Cd-B, and Cd-U and As-U were present, confirming the common source of absorption. Although there was evidence for an increased lead absorption, this was very moderate, with practically no Pb-B levels in excess of 60 micrograms/dl. A marked effect of smoking on blood cadmium levels was present; nevertheless, for all smoking categories Cd-B levels were significantly higher in active employees, indicating the independent contribution of exposure to cadmium in the smelter. Cd-U did not exceed 10 micrograms/g creatinine, the generally accepted "critical" level for the kidney, but was higher than 2 micrograms/g creatinine, a level very rarely exceeded in the general population, in a sizable proportion of those examined. The highest Cd-U levels were found in retired copper smelter employees; age might have been a contributing factor, besides a longer duration of exposure in the smelter.     

A simplified method for the quantitative determination of urinary coproporphyrin in lead workers

Soulsby, Joan and Smith, R. L. (1974).British Journal of Industrial Medicine,31, 72-74. A simplified method of estimating urinary coproporphyrin is described, based on the method of Rimington (1971). Coproporphyrin and coproporphyrinogen are extracted into ether from acidified urine; the ether is then shaken with a solution of iodine in hydrochloric acid to oxidize any coproporphyrinogen to coproporphyrin and to extract the coproporphyrin. The solution is examined spectrophotometrically for coproporphyrin at the peak of the Soret band and at wavelengths on either side to correct for any impurities present.

A comparison with the method of Rimington (1971) in 94 urine samples with coproporphyrin levels up to 2·5 mg/l showed good agreement. Correlation coefficient (r) = +0·986. One hundred estimations can be carried out in five hours.