1—（4—安替比林基）—3—（2,4—二硝基苯基）—三氮烯与汞（Ⅱ）新显色条件的…

研究了１－（４－安替比林基）－３－（２，４－二硝基苯基）－三氮烯与汞（Ⅱ）显色反应新的显色条件，建立了一个高灵敏度、高选择性的汞的分光光度方法。方法直接用于寺面水和尿液中汞的测定，其加入回收率为９４．１－１０４．４％，变异系数为３．５％，所得结果与冷原子吸收法一致。     

1－（4－安替比林基）－3－（2，4－二硝基苯基）－三氮烯与汞（Ⅱ）新显色条件的研究及其应用

研究了１－（４－安替比林基）－３－（２，４－二硝基苯基）－三氮烯与汞（Ⅱ）显色反应新的显色条件，建立了一个高灵敏度、高选择性的汞的分光光度方法。方法直接用于地面水和尿液中汞的测定，其加入回收率为９４．１～１０４．４％，变异系数为３．５％，所得结果与冷原子吸收法一致。     

汞的形态分析研究：（Ⅰ）萃取—液相色谱分离测定不同形态汞

本文报道了有机汞及无机汞与二乙基二硫代氨基甲酸盐形成络合物，经氯仿萃取后用反相高效液相色谱法进行分离测定的方法，对实验的最佳条件进行了探讨，用于测定加标西湖水样和海水中不同形态的汞含量，回收率为９３．２％－１１４％，相对标准偏差为甲基汞３．７％，乙基汞３．６％，苯基汞３．２％和无机汞３．０％，检测下限为０．２５、０．２１、０．１９和０．７２ｎｇ。     

2-羟基-3-羧基-5-磺酸基苯重氮氨基偶氮苯与汞的显色反应及其应用

研究了2－羟基－3－羧基－5－磺酸基苯重氮氨基偶氮苯（HCSDAA）与汞（Ⅱ）的显色反应。在乳化剂OP存在下和pH10．0～10．5的缓冲介质中，汞（Ⅱ）与HCSDAA形成1：2的红色络合物，其最大吸收波长是522nm，对比度为91nm，表观摩尔吸光系数为1．63×105L·mol－1·cm－1。汞（Ⅱ）在0～0．55mg／L范围内服从比尔定律。本方法操作简便，选择性较好，直接用于头发和废水的分析，6次测定的相对标准偏差分别为2．1％和27％，平均值与双硫腙法一致，回收率分别是94．8％～101．6％和98．7％～103．0％。     

冷原子吸收法测定锌精矿中的汞

采用冷原子吸收法测定出口锌精矿中汞,完善了国家标准锌精矿化学分析方法没有汞的测定方法之不足,该法测定范围为０．０５－０．３０μｇ／ｍｌ,回收率为９９．６％－１０６．５％,变异系数为１．８１％－３．０２％,能满足微量汞测定要求。     

硼氢化钠还原-无色散原子荧光法测定茶叶中汞

建立了汞的硼氢化钠还原－无色散原子荧光测定方法,在最佳条件下,荧光强度与汞浓度在0－25μg/L范围内呈线性关系,相关系数0．9991,检出限0．02μg/L。用拟定的方法测定了茶叶中的汞,回收率为91．6％－98．3％,变异系数不超过5．2％。     

极谱分析人员头发、指甲和尿中的汞含量及其评价

为查明汞在极谱分析人员体内吸收、积累与排泄情况，用无火焰原子荧光法测定了２１例极谱分析人员（检查组）和２２例非接触汞人员（对照组）头发、指甲和尿中的汞．结果表明，检查组头发、指甲和尿中汞含量均明显高于对照组（Ｐ＜０．００１）；性别之间无显著差异（Ｐ＞０．０５）；汞的积累与接触汞史有关，与年龄无关．发汞和指甲汞远比尿汞高，且含量稳定，因而头发和指甲的监测可作为血清和尿分析的补充手段，在职业病及环境医学方面甚至可代替尿汞监测。     

密闭溶样两次金泵齐冷原子吸收光谱法测定煤中微量汞

建立了密闭溶样两次金汞齐冷原子吸收光谱法测定煤样中微量汞的方法，该法具有试剂空白低的特点，适合于测定煤样中的微量汞。研究表明，该法最低检出限为２．５×１０＾－９，精密度为７．３％，回收率平均为９９．８１％。     

在线固相萃取富集-液相色谱分离冷原子吸收联机测定不同形态汞

本文报道了在线固相萃取预富集（FI）－液相色谱（HPLC）分离－冷原子吸收（CVAAS）联机技术和汞的形态分析方法。应用FI和HPLC高压接口技术，可使被测物在线富集并被HPLC洗脱液全部带入HPLC－CVAAS系统进行分离测定，富集倍数和富集时间成正比，Pb、Cu、Ni、Cd、Fe等重金属离子均不干扰。应用硼氢化钠在线还原结合加热热解，能提高有机汞测定灵敏度，MeHg、EtHg、PhHg和Hg（Ⅱ）的检测下限可达到0．86、1．94、1．06和1．92ng／L，相对标准偏差为3．8％、70％、5．5％和5．0％。尿样中无机汞能直接测定，有机汞因含量太低未检出，加标回收率分别为94％、106％、92％和102％。     

化学衍生—高效液相色谱法同时测定铅（Ⅱ）和汞（Ⅱ）

从吡啶－２－乙醛苯甲酰腙作柱前衍生试剂，在优化了衍生和色谱条件下实现了用高效液相以谱法同时测定铅和汞离子，在ｐｈｅｎｏｍｅｎｅｘｓｐｈｅｒｅｘＣ１８色谱柱上，用甲醇－水（６５：３５，Ｖ／Ｖ），作流动相，于２４８ｎｍ处检测，得到线性良好的工作曲线，铅和汞的最低检测限分别为２．５５μｇ／Ｌ和７．２９μｇ／Ｌ。分析了环境水样品和合成水样，铅和汞的标准加入回收率分别为９８．３％～１０１．７％和９８．０～１     

Activation analysis of mercury in urine samples of electrolysis cell workers

The activation method of determination of trace amounts of Hg in human urine has been studied by introducing a simple amalgam deposition method. Human urine samples were obtained from the alkali chloride, electrolysis plant equipped with Hg cells. The capacity of Cu powder for Hg quantity, the pH conditions, and the shaking time were described. The results showed that the Hg contents in workers' urine samples varied from 33 ppb to 60 ppb depending on working conditions.     

Use of a ruthenium(III), iron(II), and nickel(II) hexacyanometallate-modified graphite electrode with immobilized oxalate oxidase for the determination of urinary oxalate.

This paper describes the performance of a biosensor with an Ru(III), Ni(II), and Fe(II) hexacyanometallate-modified graphite electrode and immobilized oxalate oxidase for the determination of urinary oxalate. The addition of ruthenium enhances the electrochemical reversibility and chemical stability of the electrocrystallized layer and improves the sensitivity of the biosensor. Hydrogen peroxide, produced by the enzyme-catalyzed oxidation of oxalate, was measured at -50 mV vs an Hg Hg2CI2 3M KCl electrode in a solution of pH 3.6 succinic buffer, 0.1 M KCl, and 5.4mM ethylenediaminetetraacetic acid. The linear concentration range for the determination of oxalate was 0.18-280 microM. The recoveries of added oxalate (10-35 microM) from aqueous solution ranged from 99.5 to 101.7%, whereas from urine samples without oxalate (or with a concentration of oxalate below the detection limit) the recoveries of added oxalate ranged from 91.4 to 106.6%. The oxalate in 24 h urine samples, taken during their daily routine from 35 infants and children, was measured and found to range from 0.6 to 121.7 mg/L. There were no interferences from uric acid, acetylsalicylic acid, and urea in the concentration range investigated, but paracetamol and ascorbic acid did interfere. A good correlation (R2 = 0.9242) was found between values obtained for oxalate in real urine samples by 2 laboratories, with the proposed biosensor and ion chromatography, respectively.     

Determination of total urinary mercury by on-line sample microwave digestion followed by flow injection cold vapour inductively coupled plasma mass spectrometry or atomic absorption spectrometry

The total mercury content in urine was determined by inductively coupled plasma mass spectrometry with the so-called cold vapour method after on-line oxidative treatment of the sample in a microwave oven (FI-MW-CV-ICPMS). Use of a KBr/KBrO(3) mixture, microwave digestion, and the final oxidation with KMnO(4), assure the complete recovery of the organic forms of Hg which would be difficult to determine otherwise if using only the CV-ICPMS apparatus. Quantitative recoveries were obtained for phenyl Hg chloride (PMC), dimethyl Hg (DMM), Hg acetate (MA) and methyl Hg chloride (MMC). Use of automatic flow injection microwave systems (FI-MW) for sample treatment reduces environmental contamination and allows detection limits suitable for the determination of reference values. Since no certified reference materials were commercially available in the concentration ranges of interest, the accuracy of the proposed procedure has been assessed by analysing a series of urine samples with two independent techniques, ICP-MS and AAS. When using the FI-MW-CV-ICP-MS technique, the detection limit was assessed at 0.03microg/L Hg, while with FI-MW-CV-AAS it was 0.2microg/L Hg. The precision of the method was less than 2-3% for FI-MW-CV-ICP-MS and about 3-5% for FI-MV-CV-AAS at concentrations below 1microg/L Hg. These results show that ICP-MS can be considered as a "reference technique" for the determination of total urinary Hg at very low concentrations, such as are present in non-exposed subjects.     

Mercury speciation by coupling cold vapour atomic absorption spectrometry with flow injection on-line preconcentration and liquid chromatographic separation

A fully automated system for the direct determination of methylmercury (MeHg), ethylmercury (EtHg), phenylmercury (PhHg), and inorganic mercury (Hg(II)) at the ng/L level is described. It is based on solid phase extraction preconcentration incorporated in a flow injection (FI) system, high performance liquid chromatography (HPLC) separation, reduction combined with thermolysis and determination by cold vapour atomic absorption spectrometry (CVAAS). For preconcentration a microcolumn of bonded silica with octadecyl functional groups (C18 reversed phase material) was used as a sorbent for the mercury complexes formed on-line with ammonium pyrrolidine dithiocarbamate. Retained mercury species are eluted with a methanol-acetonitrile-water mixture and subjected to separation on an octadecylsilane (ODS) column before determination by CVAAS. The sensitivity of organo-mercury determination could be improved by using NaBH₄ as a reductant combined with a thermolysis step. In order to perform on-line measurements the preconcentration microcolumn was mounted in a pressure-tight casing. Limits of detection for MeHg, EtHg, PhHg and Hg(II) employing a sample volume of 58.5 mL were 9, 6, 10 and 5 ng/L, respectively. The relative standard deviation (RSD) calculated from 9 repeated measurements was found to be 3.6%, 5.5%, 10.4% and 7.6% for MeHg, EtHg, PhHg and Hg(II), respectively. Finally, the application of this method for speciation of mercury in fish and human urine is described.     

Mercury speciation by coupling cold vapour atomic absorption spectrometry with flow injection on-line preconcentration and liquid chromatographic separation

A fully automated system for the direct determination of methylmercury (MeHg), ethylmercury (EtHg), phenylmercury (PhHg), and inorganic mercury (Hg(II)) at the ng/L level is described. It is based on solid phase extraction preconcentration incorporated in a flow injection (FI) system, high performance liquid chromatography (HPLC) separation, reduction combined with thermolysis and determination by cold vapour atomic absorption spectrometry (CVAAS). For preconcentration a microcolumn of bonded silica with octadecyl functional groups (C18 reversed phase material) was used as a sorbent for the mercury complexes formed on-line with ammonium pyrrolidine dithiocarbamate. Retained mercury species are eluted with a methanol-acetonitrile-water mixture and subjected to separation on an octadecylsilane (ODS) column before determination by CVAAS. The sensitivity of organo-mercury determination could be improved by using NaBH₄ as a reductant combined with a thermolysis step. In order to perform on-line measurements the preconcentration microcolumn was mounted in a pressure-tight casing. Limits of detection for MeHg, EtHg, PhHg and Hg(II) employing a sample volume of 58.5 mL were 9, 6, 10 and 5 ng/L, respectively. The relative standard deviation (RSD) calculated from 9 repeated measurements was found to be 3.6%, 5.5%, 10.4% and 7.6% for MeHg, EtHg, PhHg and Hg(II), respectively. Finally, the application of this method for speciation of mercury in fish and human urine is described. Received: 10 March 1997 / Revised: 29 January 1998 / Accepted: 5 February 1998     

Determination of Mercury in Urine and Seawater by Flow Injection Vapor Generation Isotope Dilution Inductively Coupled Plasma Mass Spectrometry

A simple and inexpensive laboratory-built vapor generator was used with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of mercury in urine and seawater samples. The applications of vapor generation ICP-MS alleviated the non-spectroscopic interferences and the sensitivity problem of mercury determination encountered when the conventional pneumatic nebulizer was used for sample introduction. The concentration of mercury was determined by isotope dilution method. The isotope ratio of mercury was calculated from the peak areas of each injection peak. The repeatability of the peak areas and isotope ratio determinations of seven consecutive injections of 1 ng mL^?1 Hg solution were 2.3% and 2.2%, respectively. This method has a detection limit of 0.07 ng mL^?1 for mercury. This method was applied to determine mercury in a CASS-3 nearshore seawater reference sample, NASS-4 open ocean seawater reference sample, NIST SRM 2670 freeze-dried urine reference sample and several urine and seawater samples collected from National Sun Yat-Sen University. The results for the reference samples agreed satisfactorily with the reference values. Results for other samples analyzed by the isotope dilution method and the method of standard additions agreed satisfactorily. Precision was better than 10% for most of the determinations.     

非聚集金纳米棒比色传感器测定半胱氨酸

基于半胱氨酸（Cys）中的–SH与Hg2+配合生成稳定的Hg(Cys)₂,有效抑制抗坏血酸（Vc）还原Hg2+生成Hg0,进而抑制Hg0与金纳米棒（AuNRs）纵向部位的Au作用而生成金汞齐,导致AuNRs的纵向等离子体共振（Longitudinal surface plasmon resonance,LSPR）吸收峰红移,相应的吸光度（A）增大,并且伴随着溶液颜色的显著变化,同时随着Cys浓度的增大,吸光度A也逐渐增大,据此建立了一种快速     

Determination of oxalate in urine, using an amperometric biosensor with oxalate oxidase immobilized on the surface of a chromium hexacyanoferrate-modified graphite electrode

A novel enzymatic amperometric method is described for the determination of oxalic acid in urine. An amperometric biosensor was made by immobilizing oxalate oxidase on the surface of a chromium(III) hexacyanoferrate-modified graphite electrode by using a bovine serum albumin and glutaraldehyde cross-linking procedure. The enzyme biocatalyzes oxalate decomposition in the presence of oxygen into carbon dioxide and hydrogen peroxide. The oxalate concentration, which is proportional to the amount of hydrogen peroxide, was determined amperometrically by measuring the current resulting in the reduction of hydrogen peroxide at a very low working potential (0.05 V versus the Hg ?Hg2Cl2? 3M KCl electrode), which minimized the influence of the possible interferences present in human urine. All experiments were performed with succinic buffer, pH 3.8, containing 0.1M KCl and 5.4mM ethylenediaminetetraacetic acid. In an aqueous solution of pure oxalic acid, the biosensor showed good linearity in a concentration range of 2.5-100 microM without the use of a dialysis membrane. For untreated urine samples, a high correlation (R2 = 0.9949) was obtained between oxalate concentrations added to urine samples and oxalate recoveries calculated for determinations with the described oxalate biosensor.     

Study of extraction conditions for the quantitative determination of Hg bound to sulfide in soils from Almaden (Spain)

Almaden mine (Spain) is the largest source of cinnabar (HgS) in the world. The purpose of this study is to evaluate, compare and optimize the analytical conditions for the quantitative determination of Hg bound to sulfide in soil samples from mining area of Almaden. A sequential extraction procedure was performed in two stages. The first one was based on a nitric acid leaching. An optimization of certain extraction conditions in this stage was carried out. In order to assess the suitability of the nitric acid leaching, an additional study of possible interfering compounds that might promote the solubility of HgS in nitric acid was developed. The quantitative determination of Hg bound to sulfide was considered in a second stage. A comparative study was carried out among three different procedures: i) extraction with a saturated Na(2)S solution from the residue remaining in the first stage, ii) microwave assisted dissolution of the remaining Hg in this residue with aqua regia, and iii) quantification by difference between total Hg content and Hg extracted in the first stage.The recoveries of Hg bound to sulfide were found to be comparable for the three proposed procedures. Soil samples coming from Almaden mining area were analysed by this method. The distribution of Hg chemical forms was found to be similar for the two parcels tested, and the recoveries of bound to sulfide Hg ranged from 83% to 96% of total Hg content.     

Naked magnetite nanoparticles for both clean-up and solid-phase extraction-trace determination of mercury

A new solid-phase extraction method was developed for trace determination of Hg(II) by using a small amount of naked magnetite nanoparticles as an adsorbent. The magnetite nanoparticles were characterized by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The adsorbed Hg(II)-dithizone complex was eluted with 1.0 mL aliquot of an acidic 1-propanol solution prior to electrothermal atomic absorption spectrometry. A huge positive effect was found on the mercury adsorption by ionic strength. Under optimized condition, a linear calibration curve was obtained for mercury in the range of 0.2–50 ng mL^?1 with relative standard deviation in the range of 0.5–2.0%. The limit of detection and enrichment factor were 0.01 ng mL^?1 and 98.3, respectively. The effects of coexisting ions were studied extensively, and a new clean-up procedure was used to remove the matrix effects by using a simple sample pretreatment step using a little amount of magnetite nanoparticles. The method was successfully applied to the determination of Hg(II) in different water and human urine samples and a commercial sodium nitrate.