不同分析标准测试土壤铅镉结果比较

土壤的金属测试重点在于前处理,不同的消解方式对于测试结果有着较大的影响,我国目前现行的土壤铅、镉分析标准,主要选用《GB/T 17141-1997土壤质量铅、镉的测定石墨炉原子吸收分光光度法》(以下简称石墨炉法),该方法通过加入四酸加热使土壤完全消解,与《HJ 803-2016土壤和沉积物12种金属元素的测定王水提取-电感耦合等离子体质谱法》(以下简称ICP-MS法)王水提取或国外常用的王水提取法(如美国EPA 6020)在前处理上有较大区别。本文通过对不同质地的实际土壤样品分别使用四酸完全消解法和王水提取法分析铅、镉含量,比较发现上述两种前处理方法的分析结果相近,相对偏差较小。     

高压密闭消解ICP-AES法测土壤中的10种重金属元素

采用硝酸-氢氟酸高压密闭消解、硝酸复溶,用电感耦合等离子体原子发射法(ICP-AES)对土壤样品中10种重金属元素含量进行同时测定,通过对土壤标样的测定,并与ICP-MS法进行方法间比对,测定结果的误差在规范允许的误差范围之内。该法灵敏度高、消解完全、结果准确,是一种分析土壤中重金属元素含量的较好方法。     

氢化物发生-原子荧光光谱法测定血清中硒含量研究

采用氢化物发生-原子荧光光谱法测定血清中的硒含量。通过实验确定介质酸浓盐酸溶液的最适宜体积分数为10%,还原剂硼氢化钾溶液的最适宜质量分数为1.5%。采用干法消解、湿法消解、微波消解对样品进行前处理,研究不同的消解方法对硒含量测定的影响,实验结果表明:微波消解法优于其他两种方法,具有污染小、时间短、准确度高的优点。该方法的检出限为0.004μg/L,标准偏差为2.88%,加标回收率在94.5%~102.5%之间。微波消解-原子荧光光谱法可以快速测定大批量血清样品,缩短工时、提高效率,适用于临床检测。     

ICP-AES法测定某蔬菜地土壤中铜、锌、铅、镉

通过几种不同的消解方法,选择出适合于蔬菜地土壤消解的高效、安全、经济的前处理方法,并用ICP-AES快速测定法测定。本文采用HNO3+H2O2常压消解法、HNO3+H2O2密闭容器消解法、王水+H2O2消解法与国标四酸消解法(盐酸+硝酸+氢氟酸+高氯酸)比较。王水+H2O2消解法的回收率范围在91.95%～110.2%之间,达到了微量元素测定和回收的要求,方法简单安全。     

微波消解-ICP-MS法测定土壤及耕作物小麦中的8种重金属元素

建立微波消解-电感耦合等离子体质谱(ICP-MS)法同时测定土壤及对应耕作物小麦中8种重金属元素(Cr、Ni、Cu、Zn、As、Cd、Hg、Pb)含量的方法,比较不同的酸消解体系对土壤消解效果的影响。通过优化仪器参数、选择103Rh作单一内标元素校正土壤基体的干扰及仪器信号漂移,并编辑校正方程消除质谱干扰等,实现对土壤、小麦籽粒及小麦粉中重金属元素的准确测定。结果表明:以HNO_3-H_2O_2-HF(5∶2∶2)为消解液体系微波消解土壤时,样品消解完全且效果最佳;各元素均呈现良好的线性关系,相关系数(r2)≥0.999 5;检出限在0.005～0.15μg/L之间。土壤标准物质GBW07454(GSS-25)和小麦标准物质GSB10046(GSB-24)的测定值与标准值吻合,加标回收率在93.4%～103.6%范围内,方法精密度和准确度高。实际样品结果显示,土壤中Cd、Pb达到3级中污染水平;对应小麦籽粒和小麦粉中重金属元素与土壤存在一定的同源性,重金属元素更易富集于小麦籽粒中,其中Cd污染最严重。     

土壤重金属消解方法的探索与研究

在土壤及矿渣的重金属含量测定过程中,对样品的消解是影响其含量测定结果是否准确的关键步骤,本文通过采用不同的消解方法来分别分析土壤及矿渣中重金属含量,对土壤及矿渣样品进行铅、镉、铬、锌、镍五种金属元素含量测定,结果表明,电热板消解法,微波消解法各有优点。     

电感耦合等离子体质谱法测定土壤中痕量铊

在使用王水-HClO4-HF消解法对土壤进行消解后,采用ICP-MS法测定土壤中痕量的铊。对王水-HClO4-HF消解法中王水冷浸时间、HClO4和HF的用量进行优化,发现在土壤取样量为0.500 0 g,王水冷浸时间为4 h,HF用量为4 m L,并且在保证测定值准确的情况下不需要加入HClO4,是测量土壤中痕量的铊的最佳条件。通过一系列的实验建立一种更加准确,经济,灵敏检测土壤中痕量铊的ICP-MS方法。     

石墨炉原子吸收光谱法测定土壤中铅元素

山西省是我国重要的能源和重化工基地,由于煤矿开采、工矿企业废水的排放,造成周边土壤铅污染较严重,因此,准确检测矿区周边的铅元素很有必要.本文通过优化试验条件,使用石墨炉原子吸收法测定土壤中的铅含量,比较了微波消解和电热板两种消解方法对土壤标准物质的消解效果,测定出吕梁市某矿区周边土壤铅元素的含量.实验表明:石墨炉原子吸收法采用电热板消解,加入混酸(6mL氢氟酸、2mL高氯酸、2mL浓硝酸),该方法操作便捷,时间短,消解完全,结果可靠.在优化条件下,对购买的土壤标准物质的测定结果在标准值范围内,同时检测出3个土壤样品的含铅量分别为67.11,67.11,67.12,加标回收率分别为102.2%,94.93%,92.95%.     

土壤重金属测定方法比较

通过比较三种土壤消解方式对重金属测定结果的影响,同时列表比较三种检测方法的优缺点,建立一套环境监测实验室快速、准确测定土壤样品的方法体系:全自动石墨消解-电感耦合等离子体质谱测定。     

微波消解-电感耦合等离子体质谱法同时测定土壤样品中八种重金属元素

本文以Ge、In、Re内标校正体系,采用微波消解-电感耦合等离子体质谱（ICP—MS）对土壤样品中砷、铅、铜、锌、镉、铬、汞、镍八种重金属元素进行同时测定,通过加标回收试验,建立了土壤样品中砷、铅、铜、锌、镉、铬、汞、镍八种重金属元素ICP—MS分析方法,各元素检出限均小于1．0ng／mL,测定8种元素的相对标准偏差均小于10％,各元素的加标回收率在86．3％～101．0％。实验表明：该法操作简单、快速,灵敏度高,重现性好,而且能够对八种重金属元素进行同时测定,大大提高了检测效率。     

微波消解快速测定印染污泥中重金属

建立了微波消解-原子吸收分光光度法测定印染污泥中铜、锌、镍、铅、镉5种金属的检测方法。分别称取0.2g~0.3g标准土壤样品和印染污泥样品进行分析,标准土壤样品测定结果的相对误差为-0.99%～6.69%,5次平行测定结果的相对标准偏差为0.71%～5.66%;印染污泥样品测定结果的加标回收率为84%～113%,相对标准偏差为2.47%～9.26%。本方法具有准确、快速等优点,适用于大批量样品分析测定。     

微波消解-等离子体光谱法测定钒氮合金中硅、锰、磷、铝

建立了微波消解等离子体光谱法直接同时测定钒氮合金中Si、Mn、P、Al四种杂质元素的新方法。至目前为止,此方法未见报道。通过对微波消解试样参数、基体效应、光谱干扰、等离子体测定条件等多方面的考察,优选了检测条件。方法简便快捷、易于实际操作。各杂质离子平均回收率为95%~111%,相对标准偏差RSD小于3%。     

直接-火焰原子吸收法测定土壤中微量铅

本文进行了高压消解和敞口消解土壤样品的前处理比较实验,采用了高压消解,直接一火焰原子吸收法测定土壤样品中微量铅。方法的相对标准偏差2.2％～4.6％,回收率99％～104％,检出限0.054mg/L。     

比浊法测定土壤有效硫的探讨

对比浊法测定土壤有效硫中的前处理部分进行了改进,即采用活性碳代替H_2O_2去除有机质,活性碳用量以0.04g为最佳;对12种不同土壤采用改进的新方法测定,结果与原方法显著相关,相关系数为0.9966,相关方程为Y=3.4121+1.0531X,新方法的回收率为96.48%～101.15%,标准差为0.099～0.382,变异系数为0.547%～4.321%,与原方法相比,新方法更加快速、简便、精确、重复性和再现性均好,易于推广。     

Evaluation of an ultrasonic acid digestion procedure for total heavy metals determination in environmental and biological samples

In this study, a sample preparation method based on ultrasonic assisted acid digestion (UAD) has been evaluated for total heavy metals (Cd, Cr, Ni and Pb) determination in different environmental (soil, sediment and sewage sludge), and biological (fish muscles, vegetables and grains) samples, using electrothermal atomic absorption spectrometry (ETAAS). The investigated parameters influencing UAD such as presonication time, sonication time, temperature of ultrasonic bath, and different acid mixtures were fully optimized, whereas power was maintained constant at 100% of nominal power of ultrasonic bath. Six different sets of above parameters were applied on six certified reference materials (CRMs) having different matrices. The accuracy of the method was also tested by comparing the results with those obtained from conventional hot plate assisted acid digestion method on same CRMs. Analytical results for HMs by both methods showed no significant difference at 95% confidence limit (p<0.05). Recoveries of HMs ranging from 96.2% to 102% and 96.3% to 98.6% were obtained from biological and environmental samples, respectively. The average relative standard deviation of UAD method varied between 3.5% and 8.2%, depending on the analyte.     

Increased temperature in the thermophilic stage in temperature phased anaerobic digestion (TPAD) improves degradability of waste activated sludge

Two-stage temperature phased anaerobic digestion (TPAD) is an increasingly popular method to improve stabilisation of sewage waste activated sludge, which normally has inherently poor and slow degradation. However, there has been limited systematic analysis of the impact of the initial thermophilic stage (temperature, pH and retention time) on performance in the main mesophilic stage. In this study, we demonstrate a novel two-stage batch test method for TPAD processes, and use it to optimize operating conditions of the thermophilic stage in terms of degradation extent and methane production. The method determines overall degradability and apparent hydrolysis coefficient in both stages. The overall process was more effective with short pre-treatment retention times (1-2 days) and neutral pH compared to longer retention time (4 days) and low pH (4-5). Degradabilities and apparent hydrolysis coefficients were 0.3-0.5 (fraction degradable) and 0.1-0.4d(-1), respectively, with a margin of error in each measurement of approximately 20% relative (95% confidence). Pre-treatment temperature had a strong impact on the whole process, increasing overall degradability from 0.3 to 0.5 as temperature increased from 50 to 65 °C, with apparent hydrolysis coefficient increasing from 0.1 to 0.4d(-1).     

土壤中Ba和Mn的激光诱导击穿光谱定量检测

传统的土壤重金属元素检测方法流程复杂,时间长.我们采用波长1 064 nm的调Q脉冲Nd:YAG激光器和多通道小型光纤光栅光谱仪,建立了一套可移动的激光诱导击穿光谱系统.详细研究了重金属元素Ba,Mn的特征谱线强度、标准偏差与数据采样方式以及采样平均次数的关系,在优化工作参数的基础上,采用一种新的光谱采样和数据处理方法,对土壤中金属Ba、Mn的含量进行检测,并获得了检测土壤中金属Ba、Mn含量的定标曲线,对元素Ba、Mn的监测的相对标准偏差分别为9.0%和10.24%,检测灵敏度分别为19.4 mg/kg和115.4 mg/kg,优于目前文献报道的结果.     

微波消解-电感耦合等离子体发射光谱仪法同时测定藏香中7种重金属元素

对藏香多种重金属元素同时检测的方法较少研究。本文建立了微波消解-电感耦合等离子发射光谱仪(ICP-OES)法同时测定藏香中7种重金属元素(As、Cd、Cr、Cu、Hg、Ni、Pb)的方法。藏香样品在HNO3溶液中120℃加热30 min后采用程序升温在100、120、150、185℃下进行微波消解,消解后的溶液经ICP-OES测定。该方法对7种重金属元素在0.040~2.0 mg/L浓度范围内均具有良好的线性关系(相关系数均在0.9999以上),检出限在0.045-0.61 mg/kg之间,加标回收率在84.6%-102.9%之间,相对标准偏差小于10%。该方法可用于藏香中重金属含量的测定,并为完善藏香质量标准提供依据。     

Oxidative desulfurization: kinetic modelling

Toxicity of hexavalent chromium (Cr(6+)) was focused on with a publication of EU RoHS directive, a novel method to determine hexavalent chromium is developed. It is a combination of energy dispersion X-ray fluorescence spectrometry (EDXRF), spot test, alkali digestion and UV-vis spectrophotometric analysis. First, by EDXRF screening, the presence or absence of element Cr was established. Spot test was followed to identify the valent state of chromium because Cr(6+) and Cr(3+) normally coexist. After alkali digestion, Cr(VI) was separated without an undersired Cr(VI)-Cr(III) interconversions. With a color reagent (DPC) to chelated with Cr(VI), the solution was finally detected by a UV-vis spectrophotometer at a wavelength of 540 nm which is the basis of analyzing Cr(VI) quantitatively. Some parameters affecting analyses were studied. It was found that when pH in the final solution was 2.0, the extraction time was 60 min, the extraction temperature was 90 degrees C, pH during the extraction process was 7.5-8.5, and a mixed buffer solution (0.5M K(2)HPO(4)/0.5M KH(2)PO(4)) was added up to 1 ml, colorimetric reagent was added to 2 ml, it is optimal for extraction. Under this condition, interferences from Fe(3+), Pb(2+), Ag(+), etc., were overcome. It was also found that the curves are rectilinear in the range of 0-500 microg l(-1), the correlation coefficient is up to 0.999924, and the recovery rates are more than 85%, the Cr(III)-DPCO complex can be kept stable for 24h with a relative humidity (RH) range of 60-90%, and a temperature range of 5-40 degrees C. So it can be concluded that the proposed method has a good sensitivity and high precision. It is a more convincing and reliable method due to its relative standard deviation (R.S.D.) <1% after six replicate determinations of Cr(VI) in an Fe-Ni alloy sample.     

微波消化-原子吸收光谱法测定中成药中Cu、Pb、Hg、As

本文建立了微波消化-原子吸收光谱法测定中成药中Cu、Pb、Hg、As的方法。四种元素方法的相对标准偏差RSD％为2-4.8％,回收率在90～110％之间,定量检出限分别为6.8μgCu/g(干态)、0.41μg Pb/g(干态)、0.13μg As/g(干态)、0.1μg Hg/g(干态)。