电热蒸发-直接进样-冷原子吸收光谱法测定土壤以及沉积物中汞

采用传统分析仪器测定汞元素,需要对样品进行化学消解,存在操作繁杂、效率低以及易交叉污染等问题。故建立了电热蒸发-直接进样-HGA-100测汞仪测定土壤以及沉积物中汞的方法,无需对样品进行化学前处理,降低环境污染。通过优化HGA-100测汞仪参数条件,汞质量浓度在0~20ng以及20~200ng,相关系数优于0.998,准确称量样品0.05g(精确至0.000 1g),方法检出限为0.5μg/kg,相对标准偏差1.6%~4.6%,加标回收率在90.1%~100%。方法用于对土壤和沉积物标准物质测定,结果与标准值相符。方法高效、准确,可用于测定土壤以及沉积物中的汞。     

电热蒸发-直接进样-冷原子吸收光谱法测定土壤以及沉积物中汞

采用传统分析仪器测定汞元素,需要对样品进行化学消解,存在操作繁杂、效率低以及易交叉污染等问题。故建立了电热蒸发-直接进样-HGA-100测汞仪测定土壤以及沉积物中汞的方法,无需对样品进行化学前处理,降低环境污染。通过优化HGA-100测汞仪参数条件,汞质量浓度在0~20ng以及20~200ng,相关系数优于0.998,准确称量样品0.05g(精确至0.000 1g),方法检出限为0.5μg/kg,相对标准偏差1.6%~4.6%,加标回收率在90.1%~100%。方法用于对土壤和沉积物标准物质测定,结果与标准值相符。方法高效、准确,可用于测定土壤以及沉积物中的汞。     

催化裂解-金汞齐富集-冷原子吸收光谱仪测定土壤样品中总汞含量

为避免汞消解过程中产生的蒸发损失及前处理过程中产生器具与样品污染,通过配制汞总量为0～2、0～15和25～1 023 ng的三种不同汞浓度系列的标准工作曲线,选取9个土壤样品、3种国家土壤有证标准物质,同一样品分别进行6组平行测定,并抽取3个土壤样品进行3种不同浓度加标回收实验,以对其方法精密度和准确度进行论证,建立了催化裂解-金汞齐富集-冷原子吸收光谱法即直接测汞仪测定土壤样品中汞含量的方法。结果显示,仪器信号值与Hg总量之间均呈良好的线性关系。根据仪器多次测定空白数据结果,按照称样量0.1 g计算,方法检出为0.09 ng/g;平行测定结果相对标准偏差均小于10%,土壤标准物质测定值与参考值均相符,不同浓度的加标回收率范围为69.0%～97.0%。方法可用于批量土壤样品中汞含量的快速测定,精密度和准确度可满足测定要求,且实验过程中无需前处理消解,操作方便、快速高效。     

直接测汞仪-土壤标准物质绘制工作曲线法测定土壤中汞

采用直接测汞仪-土壤标准物质绘制工作曲线法测定土壤中的汞,样品无需前处理,减小了系统误差和基体干扰。绘制的低、高浓度标准曲线线性相关系数分别是0.999 9和0.999 7,可以准确测定汞含量在0～300ng范围内的样品,准确度高,重现性和稳定性好,相对标准偏差小于2.2%,符合土壤的检测要求,适用于大批量土壤样品的检测。     

直接测汞仪-土壤标准物质绘制工作曲线法测定土壤中汞

采用直接测汞仪-土壤标准物质绘制工作曲线法测定土壤中的汞,样品无需前处理,减小了系统误差和基体干扰。绘制的低、高浓度标准曲线线性相关系数分别是0.999 9和0.999 7,可以准确测定汞含量在0～300ng范围内的样品,准确度高,重现性和稳定性好,相对标准偏差小于2.2%,符合土壤的检测要求,适用于大批量土壤样品的检测。     

盐酸消解-原子荧光光谱仪测定土壤中总汞

本研究利用原子荧光光谱仪,探寻适合本实验室测定土壤总汞的方法。实验中对沸水浴消解和电热板消解这两种土壤样品的前处理方法、消解液种类以及仪器检测等因素进行条件试验,结果表明：土壤样品选用(1+1)盐酸溶液在沸水浴下加热消解、在热汞条件下分析待测液中的总汞含量是最佳样品消解及测定方法,该方法标准曲线的相关系数大于0.999,仪器最低检出限为0.006μg/g,精密度为1.2%~4.8%(n=7),样品准确度满足标准土样的要求。该方法快速简单,空白背景低,样品精密度准确度较高,适用于土壤中总汞的测定。     

电感耦合等离子体质谱法测定土壤中镉和总汞

建立电感耦合等离子质谱法测定土壤中镉和总汞的方法。土壤样品在电热板上用盐酸和硝酸于100℃低温消解,重量法定容,取上清液上机测定。镉和总汞含量分别在0.502~10.20 ng/g,0.212~5.010 ng/g范围内线性良好,相关系数(r2)大于0.999,土壤中镉和总汞的检出限分别为0.021,0.002μg/g,测定结果的相对标准偏差分别为1.99%,5.57%(n=6),加标回收率分别为97.5%~101.1%,87.5%~92.9%。该方法样品处理简单快捷,检出限低,准确度和精密度高,适合土壤中镉和总汞含量的测定。     

DMA-80直接测汞仪测定肥料样品中总汞含量

选择6个化学肥料样品和6个有机肥料样品,利用DMA-80直接测汞仪对肥料中的总汞进行了测定。对同一样品添加3种不同汞浓度汞标准溶液,每组3次重复,测定加标回收率在96.6%~104%;DMA-80直接测汞仪与原子荧光光谱法测定结果之间无显著差异;在实验过程中每个肥料样品利用测汞仪直接进样测定6组平行样,相对标准偏差小于5.0%;根据多次测定空白数据结果计算方法检出限为0.0137 ng。利用DMA-80测汞仪测定肥料中汞含量的方法具有操作简单、快速高效、检出限低等优点,可用于批量肥料样品中汞含量的快速测定分析。     

测汞仪直接测定食品中总汞

建立了食品中总汞快速准确的测定方法。使用测汞仪,采用样品直接进样法,对芹菜、大葱、鸡肉等10种标准物质中的汞含量进行了测定,结果表明,在0.2~100ng范围内线性良好,10种标准物质的检测结果均在标示值范围内。使用测汞仪直接测定食品中总汞含量,具有灵敏度高、快捷、不受前处理影响等优点,便于推广,适用于各类食品中总汞的快速测定。     

微波消解-原子荧光光谱法测定皮革中砷和汞

建立了皮革中砷和汞的微波消解-原子荧光光谱测定方法。在优化的实验条件下,砷、汞含量分别在0.60～150ng/mL和0.10～20ng/mL范围内线性良好。砷、汞检出限分别为0.22ng/mL和0.04ng/mL。方法测定砷的回收率为96.0%～104%,汞的回收率为95.0%～110%。方法准确、灵敏、快速、可应用于皮革样品中砷和汞的同时测定。     

王水消解-冷原子吸收光谱法测定土壤中汞

为了寻求一种更加适宜测定土壤中汞含量的测试方法,将检出限低、精密度高的冷原子吸收光谱法与便捷、高效的王水水浴消解土壤处理方式相结合,建立了王水消解-冷原子吸收光谱法测定土壤中汞。通过测定方法的线性相关性、方法检出限、准确度、精密度、加标回收率,并与原子荧光光谱法进行对比实验来评价该方法的有效性。王水消解-冷原子吸收光谱法在汞质量浓度0.0～1.0μg/L范围内线性良好,相关系数可以达到0.999 9,方法检出限为0.000 75mg/kg,土壤标准样品测试的相对标准偏差为4.0%～10.7%,实际样品加标回收率分别为93%～104%。采用原子荧光光谱法进行对比测试,原子荧光光谱法的方法检出限为0.002 5 mg/kg,相对标准偏差为4.8%～13.5%,加标回收率为104%～107%。结果表明,对于王水水浴消解土壤的方法不仅适用于原子荧光光谱法测定汞含量,同样可以应用于冷原子吸收光谱法中。所建立的王水消解-冷原子吸收光谱法具有更低的检出限,更优的准确度和精密度,有利于提高土壤样品测试的工作效率,值得推广。     

王水消解-冷原子吸收光谱法测定土壤中汞

为了寻求一种更加适宜测定土壤中汞含量的测试方法,将检出限低、精密度高的冷原子吸收光谱法与便捷、高效的王水水浴消解土壤处理方式相结合,建立了王水消解-冷原子吸收光谱法测定土壤中汞。通过测定方法的线性相关性、方法检出限、准确度、精密度、加标回收率,并与原子荧光光谱法进行对比实验来评价该方法的有效性。王水消解-冷原子吸收光谱法在汞质量浓度0.0~1.0μg/L范围内线性良好,相关系数可以达到0.9999,方法检出限为0.00075 mg/kg,土壤标准样品测试的相对标准偏差为4.0%~10.7%,实际样品加标回收率分别为93%~104%。采用原子荧光光谱法进行对比测试,原子荧光光谱法的方法检出限为0.0025 mg/kg,相对标准偏差为4.8%~13.5%,加标回收率为104%~107%。结果表明,对于王水水浴消解土壤的方法不仅适用于原子荧光光谱法测定汞含量,同样可以应用于冷原子吸收光谱法中。所建立的王水消解-冷原子吸收光谱法具有更低的检出限,更优的准确度和精密度,有利于提高土壤样品测试的工作效率,值得推广。     

双通道原子荧光光谱法同时测定土壤中的砷和汞

对现有国标检测方法(GB/T 22105.1-2008和GB/T 22105.2-2008)进行改进,采用王水水浴浸提-双通道原子荧光光谱法同时测定土壤样品中砷、汞的含量。采用土壤国家一级标准物质GSS-3,GSS-8,GSS-9与山西农田土壤样品为试验对象,筛选得到检测砷、汞元素含量最佳实验条件及仪器工作条件。砷、汞的质量浓度分别在0~150μg/L,0~2μg/L范围内与荧光强度成良好的线性关系,线性相关系数均大于0.999,砷、汞的检出限分别为0.021,0.0015 mg/kg。测定结果的相对标准偏差为1.81%~4.64%(n=8),砷、汞的样品加标回收率分别为92.7%~103.0%,82.0%~95.5%。经国家一级标准物质验证,该法检出限、准确度和精密度均满足检测要求。改良后的方法可以同时准确、快速地测定土壤中砷、汞,极大地提高了工作效率,可以更好地适应当前大量的土壤分析工作。     

水为载流-原子荧光光谱法同时测定土壤中痕量砷、汞

改变原子荧光光谱法以稀酸为载流的进样方式,以水为载流在新型双道原子荧光光谱仪上同时测定了土壤中的痕量砷(As)、汞(Hg)。方法采用王水水浴加热溶解样品,用50 g/L硫脲-抗坏血酸混合溶液预先将砷还原为+3价,保持10%(体积分数)以上盐酸浓度,不转移直接定容静置后测定。优化了仪器工作条件,详细考察了以水为载流测定的可行性,选择了同时测定As、Hg所需的硼氢化钾浓度和盐酸浓度。方法节省了酸试剂用量,操作快速,单个样品测定仅需20s左右。方法检出限As为0.005 mg/kg,Hg为0.0008 mg/kg,相对标准偏差(RSD%,n=7)在1.0%～7.4%,经土壤国家标准物质和实际样品验证,适合土壤中痕量As、Hg的同时快速测定。     

一次消解土壤样品测定汞、砷和硒

建立了测定土壤中3种挥发性元素(汞、砷、硒)的一次消解方法,确定以程序控温石墨自动消解仪+王水-氢氟酸-硼酸络合敞开体系为最佳消解体系,采用氢化物发生-原子荧光光谱法(HG-AFS)分别测定同一消解液中汞、砷、硒的含量.采用国家标物中心有证标准物质土壤环境样品GSS-1~GSS-8进行了方法验证,结果均符合标准偏差的允许范围.此消解方法相比于现行标准方法,避免了针对各元素的分次处理,简化了消解步骤,节省了前处理时间,减少了试剂消耗,提高了实验效率,适用性广、灵敏度高、检出限低,尤其适合批量样品的微量/痕量元素分析,可作为一种大规模土壤样品中重金属污染监测和治理的快捷方法.     

Quantification of mercury in soils and sediments – acid digestion versus pyrolysis

Mercury (Hg) pyrolysis techniques allow the differentation of Hg-binding forms in contaminated soils and sediments. However, data about reproducibility and accuracy of the results concerning quantification of single Hg-compounds and total Hg-concentrations are rare. Therefore the total mercury concentration of different contaminated soils and sediments determined by using a pyrolysis technique were compared to those obtained after aqua regia digestion and cold vapor atomic absorption spectroscopy Hg detection. Twenty replicates of four soil and two sediment samples containing different Hg-compounds were investigated by both methods. All samples were analyzed without any pretreatment. For most of the samples total Hg-concentrations determined by pyrolysis show lower values, and up to threefold higher relative standard deviation(s) (RSD) than those obtained after wet digestion. Soil samples containing specified Hg-compounds like metallic Hg (Hg⁰) or cinnabar (α-HgS) show by far higher RSD by means of both methods than samples containing only matrix-bound Hg-compounds. Single peak integration indicate that the distribution of Hg⁰ and cinnabar is usually heterogeneous resulting in RSD of up to 85%, whereas RSD of matrix-bound Hg-compounds were always distinctly lower. Besides the higher standard deviation the pyrolysis technique has been found to be reliable for screening contaminated soils and sediments due to the important additional information about occurring Hg-binding forms. Received: 13 February 1997 / Revised: 13 March 1997 / Accepted: 17 March 1997     

水载流-原子荧光光谱法同时测定土壤中痕量砷、汞

改变原子荧光光谱法以稀酸为载流的进样方式,以水为载流在新型双道原子荧光光谱仪上同时测定了土壤中的痕量砷(As)、汞(Hg).采用王水水浴加热溶解样品,用50 g/L硫脲-抗坏血酸混合溶液预先将砷还原为As(Ⅲ),保持10％(体积分数)以上盐酸浓度,不转移直接定容静置后测定.优化了仪器工作条件,详细考察了以水为载流测定的...     

Atomic absorption spectrometric determination of mercury in soil standard reference material following microwave sample pretreatment

Several decomposition procedures and their influence on the determination of mercury by electrothermal (ET) and cold vapour (CV) atomic absorption spectrometry (AAS) have been studied. Soil samples were decomposed by microwave digestion in closed and open vessels as well as by digestion under reflux according to German standard. The use of different acids (HNO₃, HCl or aqua regia) was evaluated and compared in respect to their influence on the determination of mercury by ET AAS and CV AAS. The digestion solutions were analyzed by ET AAS with a palladium modifier and by CV AAS using SnCl₂ or NaBH₄, as reducing agents. The detection limits obtained with different procedures were also evaluated. For the soil containing 6.25 g/g of Hg the ET AAS measurements were possible. In the case of lower concentration of mercury the CV AAS determination following the microwave digestion procedure with HCl or aqua regia is recommended. The accuracy of the proposed procedure was confirmed by the determination of total mercury in SRM 2711 Montana Soil.On leave from: Institut für Analytische Chemie, Technische Universitat Wien, Getreidemarkt 9, A-1060 Wien, Austria     

Arsenic speciation in contaminated soils

A method for arsenic speciation in soils is developed, based on extraction with a mixture of 1 mol l(-1) of phosphoric acid and 0.1 mol l(-1) of ascorbic acid, and further measurement with the coupling liquid chromatography (LC)-ultraviolet (UV) irradiation-hydride generation (HG)-inductively coupled plasma mass spectrometry (ICP/MS). The stability of the arsenic species in the extracts is also studied. The speciation method applied to several Spanish agricultural contaminated soils from the Aznalcollar zone shows that arsenate is the main species in all the soils analysed and that in some samples arsenite and methylated species could also be detected. The determination of the "pseudototal" arsenic in these soils, obtained by applying extraction with aqua regia (ISO Standard 11466), is also carried out. Both the speciation method and the aqua regia method are applied to several certified reference materials (CRMs) in which total arsenic content is certified. Finally, the same LC-UV-HG coupling with atomic fluorescence spectrometry (AFS) detection reveals to be a valid coupling system to perform arsenic speciation in the soils according to its fair quality parameters and easy utilisation.     

Critical comparison of two standard digestion procedures for the determination of total mercury in natural water samples by cold vapour atomic absorption spectrometry

Two pretreatment procedures for total mercury determinations in natural water samples were compared. The first, the Swedish Standard method (DP1), involves digestion of water in the presence of concentrated nitric acid at 120°C and under pressure for 30 min. In the West German Standard method (DP2), small volumes of nitric and sulphuric acids, permanganate and peroxodisulphate are added to the sample, and digestion proceeded at 50°C in an ultrasonic bath. Mercury was determined after both digestion procedures using a modified cold vapour atomic absorption spectrometric method, in which mercury generated on addition of a reducing agent is collected and subsequently atomized in a platinum-lined graphite furnace. The efficacy of the two digestion procedures was tested using various standard organic mercury compounds and it was found that only DP2 provided quantitative recoveries. Purification of the reagents required by DP2 was achieved using a mercury-selective ion-exchange resin, Chelite S, resulting in blank levels below 1.5 ng Hg l^?1. Both methods were applied to the determination of total mercury in an unpolluted marsh water sample, giving 2.0 ng Hg l^?1 (DP1) and 2.7 ng Hg l^?1 (DP2). The West German Standard digestion procedure (DP2) is recommended for the determination of total mercury in natural water samples.