微波辅助萃取-HPLC-AFS联用技术检测土壤样品中砷的化学形态

建立了微波辅助萃取-高效液相色谱(HPLC)-原子荧光光谱(AFS)联用技术分析土壤中亚砷酸盐[As(Ⅲ)]、二甲基砷(DMA)、一甲基砷(MMA)和砷酸盐[As(Ⅴ)]等4种形态砷。用正交实验设计优化了功率、萃取溶剂体积、萃取温度、萃取时间等微波萃取条件。方法的线性范围为1.00~100μg/L,As(Ⅲ)、DMA、MMA和As(Ⅴ)的检出限分别为0.21、0.33、0.38、0.56μg/L,相对标准偏差为4.6%~5.5%,样品回收率为78.1%~94.4%。用该法分析了4种土壤样品中的砷形态。     

高效液相色谱-原子荧光光谱联用分析土壤中形态砷

采用高效液相色谱(HPLC)-原子荧光光谱(AFS)联用技术分析土壤中亚砷酸盐[As(Ⅲ)]、二甲基砷(DMA)、一甲基砷(MMA)和砷酸盐[As(Ⅴ)]等4种形态砷,以磷酸为提取剂、抗坏血酸为还原剂,优化了水浴提取条件。As(Ⅲ)、DMA、MMA和As(Ⅴ)在7 min之内实现了完全分离,在1.00μg/L～100μg/L范围内线性良好,实验室检出限分别为0.25μg/L、0.36μg/L、0.39μg/L和0.51μg/L,土壤标准样品平行测定的RSD≤7.4%,加标回收率为79.5%～95.0%,提取率为74.6%～90.4%。     

氢化物发生原子吸收法测定土壤和沉积物中的砷

氢化物发生原子吸收光谱法测定题述样品中的总砷,不预还原As(V),未见报道。本文应用改良单纯形法确定了使As(V)与As(Ⅲ)同时达到相同的最大灵敏度的测定条件,因而测总砷时不预还原As(Ⅴ)。实验表明用盐酸浸泡土壤样品不能把样品中的砷完全浸提出来。改用王水浸泡处理样品测定土壤和沉积物标准参考物质中的砷,结果满意。     

用DPP法测定饮用水中痕量As（Ⅲ）和总无机砷

砷是一种剧毒的痕量元素,其毒性取决于砷的化学形态.笔者用DDP法测定饮用水中痕量AS(Ⅲ)和总无机砷,克服了原子吸收光谱法或发射光谱法对微量H_3As的测定困难,测定速度又比溶出伏安法快,且精密度高,虽然其方法的灵敏度低于溶出伏安法,但检测限是允许的.1 操作条件:仪器参数、支持电解质、去除干扰物、As(V)还原为 As(Ⅲ).     

南通地区地下水中砷的形态分布特征研究

2012年开展南通市1∶50000水文地质调查，对监测网内地下水进行采样分析，建立了基于液相色谱－电感耦合等离子体质谱联用测定地下水中砷形态的方法，该方法检出限为0．1μg／L。样品分析表明，南通地区地下水中砷的形态以三价无机砷为主，有机砷以砷胆碱（AsB）和乙基砷（DMA）为主，样品中未检出五价无机砷。通过砷形态研究表明，南通近海地区地下水中砷的质量浓度较低（＜0．5μg／L），主要以 As（Ⅲ）为主，不存在其他砷的形态；近长江地区地下水中砷的质量浓度较高（＞1．0μg／L），砷形态以 As（Ⅲ）和 DMA为主。     

高效液相色谱-电感耦合等离子体质谱法测水中不同形态砷

采用高效液相色谱(HPLC)分离水中两种常见的砷形态As(III)、As(V),电感耦合等离子体质谱系统进行检测鉴定,利用C8色谱柱,探讨了甲醇含量、磷酸二氢钾浓度、四丁基氢氧化铵浓度、p H等测试条件,由此建立了水中砷形态的分析方法。结果表明,以1.5 mmol/L磷酸二氢钾、2 mmol/L四丁基氢氧化铵(TBAOH)、5%甲醇作为流动相,调节流动相为p H 5.5,流速为1.4 m L/min,上述两种不同形态的砷可在5.5 min内得以有效分离,As(III)、As(V)检出限分别为0.001、0.01μg/L,定量下限分别为0.005、0.03μg/L。该方法实现了对水中常见的不同形态砷(As(III)、As(V))的同时分析,具有灵敏度高、选择性好、检测速度快的特点,在水质分析领域具有重要意义与应用价值。     

氨基化有机-无机杂化整体柱分离富集环境水中五价砷

将四乙氧基硅烷(TEOS)和N-(β-氨乙基)-γ-氨丙基三乙氧基硅烷(AEAPTES)作为共聚前体,采用在毛细管内原位聚合的方式制备得到氨基功能化的有机-无机杂化整体柱,将其作为针式固相微萃取(SPME)介质,建立了现场分离富集环境水中As(V)的SPME方法,优化了有机-无机杂化整体柱富集As(V)的实验条件,并研究了整体柱对As(V)的吸附/洗脱性能和富集能力,实现了环境水样中As(V)的高效、快速、高选择性检测。     

燃煤电厂周边河流中氟、砷和重金属污染健康风险评价

通过在某燃煤电厂周边河流中布设15个采样点,监测其中氟(F)、砷(As)和重金属的含量,并评价其通过饮水和皮肤接触途径对不同人群所产生的健康风险。结果表明:河流中F、As、Cd、Cr监测值均未超过《地表水环境质量标准》(GB 3838—2002)Ⅲ类标准限值,Hg严重超标;河流中污染物所致儿童和成人健康危害的总风险分别为2.62×10~(-5) a~(-1)和1.76×10~(-5) a~(-1),均高于瑞典环保局、荷兰建设和环境部推荐的最大可接受风险水平1.0×10~(-6) a~(-1),其中As、Cr对儿童的健康危害风险较大,分别为1.69×10~(-5) a~(-1)和9.21×10~(-6) a~(-1),应作为风险决策管理的重点。     

环境水样中痕量砷(Ⅲ)的荧光动力学分析

基于酸性介质中As(Ⅲ)能催化碘酸钾氧化丁基罗丹明B使其荧光猝灭,建立了测定痕量As(Ⅲ)的新方法。在最佳实验条件下,测定As(Ⅲ)的线性范围为16~320ng/ml,方法的检出限为5·7ng/ml。平行测定浓度为80ng/ml和160ng/ml的As(Ⅲ)标准溶液的相对标准偏差分别为2·0%和0·92%。并考察了二十多种物质的干扰情况。该方法已用于自来水、地表水、地下水等环境水样中痕量As(Ⅲ)分析。     

国产与进口HPLC-ICP-MS联用仪器在砷形态分析方面的比较

比较了国产与进口HPLC-ICP-MS联用仪器在环境水样砷形态分析中的应用。国产和进口HPLC-ICP-MS联用仪器均能实现亚砷酸盐、二甲基砷、一甲基砷和砷酸盐的同时测定。国产仪器出峰时间较快,优于进口仪器。但是进口仪器上亚砷酸盐和二甲基砷的分离度优于国产仪器。国产仪器和进口仪器分析亚砷酸盐、二甲基砷、一甲基砷和砷酸盐,标准曲线的线性相关系数均大于0.995。国产仪器分析4种形态砷检出限范围为0.29~0.59μg/L,进口仪器分析4种形态砷检出限范围为0.24~0.36μg/L,没有数量级上的差异。国产仪器相对标准偏差范围为1.8%~9.0%,进口仪器相对标准偏差范围为0.8%~8.9%。精密度方面国产仪器和进口仪器水平相当。实际样品加标实验,国产仪器回收率范围为86.2%~112%,进口仪器回收率范围为96.4%~114%;使用进口仪器和国产仪器测定4种形态砷的有证标准物质,测定结果无显著性差异。国产HPLC-ICP-MS联用仪器可以满足砷形态检测分析的要求。对2款仪器的比较研究,为广大企事业单位及科研院所在选择HPLC-ICP-MS联用仪器时提供有价值的基础数据和参考建议。     

The impact of a rice based diet on urinary arsenic

Rice is elevated in arsenic (As) compared to other staple grains. The Bangladeshi community living in the United Kingdom (UK) has a ca. 30-fold higher consumption of rice than white Caucasians. In order to assess the impact of this difference in rice consumption, urinary arsenicals of 49 volunteers in the UK (Bangladeshi n = 37; white Caucasians n = 12) were monitored along with dietary habits. Total urinary arsenic (As(t)) and speciation analysis for dimethylarsinic acid (DMA), monomethylarsonic acid (MA) and inorganic arsenic (iAs) was conducted. Although no significant difference was found for As(t) (median: Bangladeshis 28.4 μg L(-1)) and white Caucasians (20.6 μg L(-1)), the sum of medians of DMA, MA and iAs for the Bangladeshi group was found to be over 3-fold higher (17.9 μg L(-1)) than for the Caucasians (3.50 μg L(-1)). Urinary DMA was significantly higher (p < 0.001) in the UK Bangladeshis (median: 16.9 μg DMA L(-1)) than in the white Caucasians (3.16 μg DMA L(-1)) as well as iAs (p < 0.001) with a median of 0.630 μg iAs L(-1) for Bangladeshi and 0.250 μg iAs L(-1) for Caucasians. Cationic compounds were significantly lower in the Bangladeshis (2.93 μg L(-1)) than in Caucasians (14.9 μg L(-1)). The higher DMA and iAs levels in the Bangladeshis are mainly the result of higher rice consumption: arsenic is speciated in rice as both iAs and DMA, and iAs can be metabolized, through MA, to DMA by humans. This study shows that a higher dietary intake of DMA alters the DMA/MA ratio in urine. Consequently, DMA/MA ratio as an indication of methylation capacity in populations consuming large quantities of rice should be applied with caution since variation in the quantity and type of rice eaten may alter this ratio.     

液液萃取-气质联用法测定饮用水源地水中SVOCs

采用乙酸乙酯-正己烷混合溶剂（体积比为2∶1）对饮用水源地水中阿特拉津、林丹、邻苯二甲酸二正丁酯（DBP）、邻苯二甲酸二（2-乙基己基）酯（DEHP）和滴滴涕（含4种）等8种半挥发性有机物进行1次水样萃取，用气质联用法同时测定。试验表明，方法在25．0μg/L～500μg/L范围内线性良好；检出限在0．006μg/L ～0．028μg/L 之间；空白水样3个质量浓度水平的加标回收率为87．6％～109％，平行测定6次的 RSD＜5．1％；测定集中式生活饮用水源地的实际水样，未检出目标化合物，加标回收率为98．6％～109％。     

固相萃取-高效液相色谱法测定水中呋喃丹、甲萘威和阿特拉津

采用固相萃取-高效液相色谱(SPE - HPLC)二极管阵列检测器同时测定水中呋喃丹、甲萘威和阿特拉津,以甲醇-水为流动相,采用梯度洗脱方式,选择220 nm为检测波长,二氯甲烷为洗脱剂.呋喃丹在0.200 mg/L ～5.00 mg/L、甲萘威和阿特拉津在0.020 mg/L～5.00 mg/L范围内线性良好,检出限...     

Arsenic speciation in human hair: a new perspective for epidemiological assessment in chronic arsenicism

The analysis for arsenic in hair is commonly used in epidemiological studies to assess exposure to this toxic element. However, poor correlation between total arsenic concentration in hair and water sources have been found in previous studies. Exclusive determination of endogenous arsenic in the hair, excluding external contamination has become an analytical challenge. Arsenic speciation in hair appears as a new possibility for analytical assessing in As-exposure studies. This study applied a relative simple method for arsenic speciation in human hair based on water extraction and HPLC-HG-ICP-MS. The concentration of arsenic species in human hair was assessed in chronically As(V)-exposed populations from two villages (Esqui?a and Illapata) of the Atacama Desert, Chile. The arsenic concentrations in drinking water are 0.075 and 1.25 mg L(-1), respectively, where As(V) represented between 92 and 99.5% of the total arsenic of the consumed waters. On average, the total arsenic concentrations in hair from individuals of Esqui?a and Illapata were 0.7 and 6.1 microg g(-1), respectively. Four arsenic species, As(III), DMA(V), MMA(V) and As(V), were detected and quantified in the hair extracts. Assuming the found species in extracts represent the species in hair, more than 98% of the total arsenic in hair corresponded to inorganic As. On average, As(III) concentrations in hair were 0.25 and 3.75 microg g(-1) in Esqui?a and Illapata, respectively; while, the As(V) average concentrations were 0.15 and 0.45 microg g(-1) in Esqui?a and Illapata, respectively. Methylated species represent less than 2% of the extracted As (DMA(V)+ MMA(V)) in both populations. As(III) in hair shows the best correlation with chronic exposure to As(V) in comparison to other species and total arsenic. In fact, concentrations of As(total), As(III) and As(V) in hair samples are correlated with the age of the exposed individuals from Illapata (R= 0.65, 0.69, 0.57, respectively) and with the time of residence in this village (R= 0.54, 0.71 and 0.58, respectively).     

离子色谱法测定地表水和饮用水中亚氯酸盐、溴酸盐和氯酸盐

采用KOH梯度淋洗离子色谱法测定地表水和饮用水中ClO2-、BrO3-和ClO3-，在试验确定的条件下，3种离子与F-、Cl-、NO2-、NO3-、SO2-4、Br-、I-等7种离子分离度良好。 ClO2-、BrO3-、ClO3-在50．0μg/L～1000μg/L范围内线性良好，检出限分别为5．2μg/L、8．9μg/L、7．6μg/L，环境水样加标平行测定的RSD分别为2．1％～5．4％、4．1％～5．4％、2．5％～4．8％，两个质量浓度水平加标的平均回收率分别为93．7％～96．5％、90．3％～94．8％、98．7％～111％。     

Arsenic concentration and speciation in five freshwater fish species from Back Bay near Yellowknife, NT, CANADA

The concentration of total arsenic and five different arsenic species [As(III), As(V), monomethylarsonic acid (MMA), dimethylarsenic acid (DMA), and arsenobetaine (AsB)], were measured in the muscle, liver and gastrointestinal tract (GIT) of five different fish species [lake whitefish (Coregonus clupeaformis), walleye (Stizostedion vitreum), northern pike (Esox lucius), white sucker (Catostomus commersoni) and longnose sucker (Catostomus catostomus)] from Back Bay, Great Slave Lake, near the city of Yellowknife, NT, Canada. The total concentration (dry weight) of arsenic in muscle ranged from 0.57 to 1.15 mg/kg, in the liver from 0.42 to 2.52 mg/kg and in the GIT from 1.48 to 8.92 mg/kg. Among fish species, C. commersoni had significantly higher total arsenic concentrations in the GIT than S. vitreum, E. lucius and C. clupeaformis, and higher total arsenic concentrations in the liver than C. clupeaformis. The mean concentration of As(III) and As(V) in the muscle of all fish ranged from < or =0.01 to 0.05 mg/kg and < or =0.01 to 0.02 mg/kg, respectively, and together comprised < or =7.5% of the total arsenic measured in muscle. The concentrations of MMA were below detection in the muscle of all five fish species. However, AsB and DMA were measured in all fish species and nearly all fish tissues. The concentrations of AsB ranged from 0.01 to 0.13 mg/kg and the concentrations of DMA ranged from <0.02 to 0.45 mg/kg. The majority (>50%) of organic arsenic in almost all of the tissues from fish caught in Back Bay was not directly identified. Evidence from the literature suggests that most of these other organic arsenic species were likely trimethylated arsenic compounds, however, further analytical work would need to be performed to verify this hypothesis.     

Speciation of arsenic using solid phase extraction cartridges

Various solid phase extraction (SPE) cartridges were investigated for speciation of arsenite [As(III)], arsenate [As(v)], monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). Cartridges containing different types of sorbent materials were tested for arsenic retention and elution characteristics. Alumina cartridges were found to completely retain all the four target arsenic species, and are suitable for removal and preconcentration purposes. For speciation analysis, different arsenic species were separated on the basis of their selective retention on and elution from specific cartridges. DMA was retained on a resin-based strong cation exchange cartridge and eluted with 1.0 M HCl. MMA and As(v) were both retained on a silica-based strong anion exchange cartridge and sequentially eluted with 60 mM acetic acid (for MMA) and 1.0 M HCl [for As(v)]. As(III) was not retained on either cartridge and remained in solution. Arsenic species in solution and those eluted from the cartridges were subsequently quantified by using flow injection with hydride generation atomic fluorescence spectrometry (FI-HGAFS) and hydride generation atomic absorption spectrometry (FI-HGAAS). A detection limit of 0.05 microg L(-1) arsenic in water sample was achieved using HGAFS. An application of the method was demonstrated at a drinking water treatment facility. As(III) and As(v) species were determined in water at various stages of treatment. The method is suitable for routine determination of trace levels of arsenic in drinking water to comply with more stringent environmental regulations.     

Determination of arsenic species in fish, crustacean and sediment samples from Thailand using high performance liquid chromatography (HPLC) coupled with inductively coupled plasma mass spectrometry (ICP-MS)

Suitable techniques have been developed for the extraction of arsenic species in a variety of biological and environmental samples from the Pak Pa-Nang Estuary and catchment, located in Southern Thailand, and for their determination using HPLC directly coupled with ICP-MS. The estuary catchment comprises a tin mining area and inhabitants of the region can suffer from various stages of arsenic poisoning. The important arsenic species, AsB, DMA, MMA, and inorganic arsenic (As III and V) have been determined in fish and crustacean samples to provide toxicological information on those fauna which contribute to the local diet. A Hamilton PRP-X100 anion-exchange HPLC system employing a step elution has been used successfully to achieve separation of the arsenic species. A nitric acid microwave digestion procedure, followed by carrier gas nitrogen addition- (N2)-ICP-MS analysis was used to measure total arsenic in sample digests and extracts. The arsenic speciation of the biological samples was preserved using a Trypsin enzymatic extraction procedure. Extraction efficiencies were high, with values of 82-102%(As) for fish and crustacean samples. Validation for these procedures was carried out using certified reference materials. Fish and crustacean samples from the Pak Pa-Nang Estuary showed a range for total arsenic concentration, up to 17 microg g(-1) dry mass. The major species of arsenic in all fauna samples taken was AsB, together with smaller quantities of DMA and, more importantly, inorganic As. For sediment samples, arsenic species were determined following phosphoric acid (1 M H3PO4) extraction in an open focused microwave system. A phosphate-based eluant, pH 6-7.5, with anion exchange HPLC coupled with ICP-MS was used for separation and detection of AsIII, AsV, MMA and DMA. The optimum conditions, identified using an estuarine sediment reference material (LGC), were achieved using 45 W power and a 20 minute heating period for extraction of 0.5 g sediment. The stability and recovery of arsenic species under the extraction conditions were also determined by a spiking procedure which included the estuarine sediment reference material. The results show good stability for all species after extraction with a variability of less than 10%. Total concentrations of arsenic in the sediments from the Pak Pa-Nang river catchment and the estuary covered the ranges 7-269 microg g(-1)and 4-20 [micro sign]g g(-1)(dry weight), respectively. AsV was the major species found in all the sediment samples with smaller quantities of AsIII. The presence of the more toxic inorganic forms of arsenic in both sediments and biota samples has implications for human health, particularly as they are readily 'available'.     

超高压液相色谱/质谱联用法测定地表水中特定污染物

采用超高压液相色谱/质谱联用法测定地表水特定项目中包括微囊藻毒素-LR在内的13种污染物,对测定条件进行优化,使得各目标化合物均能在3min内检测完毕.试验表明,方法在各测定范围内线性良好,相关系数均〉0.99,各目标化合物的方法检出限为0.12μg/L～8.40μg/L,地表水样的加标回收率在62.0% ～104%之间,6次平行测定的RSD〈6%.用该方法测实际水样,阿特拉津和马拉硫磷被检出,质量浓度分别为0.6μg/L和0.7μg/L.