碱消解-离子色谱与电感耦合等离子体质谱(IC-ICP-MS)法测定土壤中的六价铬

采用碱消解土壤溶液提取土壤溶液中的六价铬,用离子色谱(IC)进行分离,有效避免了高盐及焰色反应的干扰,电感耦合等离子体质谱(ICP-MS)法进行检测。研究了消解液使用量、消解温度、消解时间等因素,测定结果和火焰原子吸收光谱(FAAS)法进行对比。结果表明,当称样量为5.0 g,消解液40.0 mL,磷酸缓冲溶液0.4 mL,无水氯化镁0.4 g,消解温度在90～95℃范围内消解0.75 h能保证土壤中六价铬的完全提取。方法检出限为0.01 mg/kg,相对标准偏差为3.5%,土壤标准物质的回收率为92.4%;与FAAS法(检出限0.35 mg/kg,精密度为6.3%)相比,检出限更低,精密度更好,抗干扰能力强;通过实际样品的测定结果统计学检验,两种方法结果无显著性差异;方法适用于土壤中低浓度六价铬的测定。     

微波消解-石墨炉原子吸收光谱法测定植物染发剂中的铅镉铜

建立了微波消解-石墨炉原子吸收光谱法测定植物染发剂中重金属铅、镉和铜的方法.采用L9(34)正交设计讨论了固液比、消解剂体积比、消解时间和消解压力对样品消解效果的影响,最佳的消解条件:固液比(g/mL)为1∶12,HNO3/H2O2(V/V)为4∶1,消解时间为5min,消解压力1.5MPa.在最佳微波消解条件下,进行了精密度实验、回收率实验,相对标准偏差为1.05%~3.35%,回收率为96.67%~105.43%.微波消解法处理植物染发剂样品,试剂用量少、消解完全、快速、简便,而且测定结果的精密度、准确度较好.     

电感耦合等离子体原子发射光谱法测定玩具包装物中六价铬和镉、汞、铅

用常规酸消解法或微波消解法消解样品,电感耦合等离子体原子发射光谱法(ICP-AES)测定了玩具包装物中的铬、镉、汞、铅的含量.对六价铬、镉、汞、铅的总含量超过100 mg·kg-1的样品,用共沉淀分离消解液中三价铬后,再用ICP-AES测定六价铬的含量,建立了玩具包装物中六价铬、镉、汞、铅的快速分析方法.方法的回收率为91.2%～103.5%,相对标准偏差(n=11)均小于3%.     

微波消解-电感耦合等离子体发射光谱(ICP-OES)法测定生物质中的碱金属和碱土金属

为研究并解决测试生物质样品中碱金属和碱土金属含量的干扰,采用微波消解-电感耦合等离子体发射光谱(IC P-O ES)法对生物质中的碱金属和碱土金属钾、钙、钠、镁元素进行测定,考察了样品消解后不同的酸体系,共存元素干扰对钾、钠、钙、镁含量测定的干扰研究.经过研究表明,接近分析标准曲线酸浓度的样品干扰小,铅、铟、钛、锰元素...     

落叶松与白桦树中微量及稀土元素的ICP-MS检测方法研究

利用微波消解法处理植物灰分样品,讨论了混合酸组成、混酸配比、固液比和微波消解时间对样品制备结果的影响.优选微波消解方案:微波压力(MPa)0.5、1.0、1.5、2.0,消解时间(min)4、3、3、10的微波程序,混合酸体系HNO3-HCl-HF-HClO4(体积比为6 ∶ 2 ∶ 1 ∶ 1).在此条件下, 进行了方法准确度实验和测量结果重复性实验, 该方法经植物国家标准物质(GBW07603)验证,微量元素测试结果的相对误差为1.06% ～5.60%,相对标准偏差为0.87% ～5.25%;稀土元素测试结果的相对误差为1.82% ～10.2%,相对标准偏差为2.14% ～8.00%.应用电感耦合等离子体质谱法(ICP-MS)同时测定植物灰分中21种微量元素和15种稀土元素.结果表明, 微波消解法处理植物灰分样品, 具有快速、简便、节省试剂、消解完全等特点, 测定结果的准确度和精密度令人满意.     

石墨消解-动态反应池模式-电感耦合等离子体质谱法测定烟用香精和料液中5种元素的含量北大核心CSCD

将烟用香精和料液样品0.3 g(精确至0.001 g)置于全自动石墨消解仪消解罐中,分3次加入消解液(共计10 mL硝酸、1 mL高氯酸),在170℃的最高消解温度下,样品消解完全.所得溶液用水定容至50 mL,采用电感耦合等离子体质谱法(ICP-MS)测定其中砷、铅、镉、铬、镍等元素的含量.以铟为内标,铬、镉、镍、铅、砷元素的测量同位素分别为^(52)Cr、^(111)Cd、^(60)Ni、^(208)Pb、^(75)As,使用动态反应池(DRC)模式消除了铬、砷元素的质谱干扰,铬、镉、镍、铅等元素的测定选择氦气碰撞模式,砷元素的测定选择氢气反应模式.结果表明,5种元素的质量浓度在一定范围内与各元素与内标计数值的比值呈线性关系,检出限(3s)为0.016~0.035 mg·kg^(-1).按标准加入法进行回收试验,各元素回收率为91.5%~111%,相对标准偏差(n=6)为0.28%~3.1%.方法用于10个烟用香精和料液样品的分析,铬、砷、镍的检出量分别为0.019~0.061 mg·kg^(-1),0.039~0.061 mg·kg^(-1)和0.022~0.031 mg·kg^(-1),镉和铅未检出.     

TXRF法测定松花粉中的9种生命元素

建立了微波消解前处理,全反射X射线荧光法(TXRF)同时测定松花粉中K、Ca、Ti、Mn、Fe、Ni、Cu、Zn和Rb9种生命元素含量的分析方法.松花粉原料经过微波消解前处理后,采用全反射X射线荧光光谱净计数、QXAS分析软件解谱和单一内标法进行定量分析.比较了干灰化法、湿消解法和微波消解法3种前处理方法的效果,并确立微波消解法作为样品前处理方法.用微波消解- TXRF法测定了花粉标准物质中的上述9种元素,并计算得到其仪器检出限(LLD)为0.002～0.054 mg/L,方法检出限(LDM)为0.004～0.122 mg/kg.TXRF法测定各元素的相对标准偏差(RSDs)为1.0％～5.5％.该方法操作简单、样品用量少、检出限低,对实际样品松花粉的测定结果与ICP - MS法无显著性差异.     

微波/电热板组合消解-电感耦合等离子体质谱(ICP-MS)法测定土壤中重金属元素

为提高土壤检测的重金属得率,采用了微波消解/电热板组合预处理-电感耦合等离子体质谱法(ICP-MS)测定土壤重金属含量。分析了硝酸(HNO3)、氢氟酸(HF)、高氯酸(HClO4)和盐酸(HCl)组合消解液及赶酸温度对土壤预处理影响。结果显示：在硝酸和盐酸混合消解液中,硝酸占比越高,铬(Cr)、钴(Co)、铜(Cu)、镉(Cd)得率更高;消解液体系中加入氢氟酸可使消解更加彻底,提高铬与铜的得率。最优预处理消解条件为硝酸 6ml+ 氢氟酸 2ml消解液组合进行微波消解,1ml 高氯酸于155℃电热板上赶酸。经土壤标准样品GBW07401(GSS-1)和GBW07452(GSS-23)实际应用,预处理条件优化后测试准确度和稳定性均显著提高。此外使用元素铑(Rh)作为内标物时,其方法稳定性和准确性高于内标物钪(Sc)和锗(Ge)。可为相关国家土壤重金属测定标准的修制订提供方法学参考。     

微波消解-ICP-OES法同时测定化妆品中Pb、As、Hg

采用微波消解ICP-OES法同时测定化妆品中Pb、As、Hg的含量,并对ICP-OES法测定化妆品消解液时分析线的选择,入射功率、泵速的影响,以及进行检测限、准确度、精密度的研究.用微波消解ICP-OES法测试化妆品中重金属检测结果快速准确.     

不同前处理方法-ICP-MS测定土壤中的重金属

采用电热板消解法、高压罐消解法和微波消解法同时消解环境土样标准物质ESS-1、ESS-2、ESS-3和ESS-4,用四级杆电感耦合等离子体质谱法(ICP-MS)分别测定其中Cd、Pb、Cu、Zn和Ni的含量,对3种方法的消解效果进行对比.结果表明:检出限方面,3种方法检出限均达到μg/L或更低,电热板消解时Zn的检出限较其他两种前处理方法高一个数量级;在重复性上,测定5种元素的相对标准偏差均小于10%,但电热板消解的重复性不如其他两种方法;准确度方面,微波消解最好,3种消解方法下重金属的测定值与保证值的线性相关系数分别为0.9983、0.9984和0.9990,电热板和高压罐消解时Pb测定结果的个别值比保证值下限稍低,其他元素测定值均在保证值范围内;方法可操作性上,电热板和高压罐消解费时费力,易交叉污染,产生的酸雾对人体伤害大,消解液定容后需静置或离心方可上机测定;微波消解高效快速、无污染、对易挥发组分无损失,且消解液定容后可直接测定,但一次消解的样品数少.     

碱消解-火焰原子吸收光谱法测定土壤中六价铬

建立了碱消解-火焰原子吸收光谱法测定土壤中六价铬的方法.讨论了pH值对六价铬测定的影响.干扰实验的结果表明同等含量的三价铬对六价铬测定无干扰.实验对比了无背景校正、氘灯背景校正、塞曼背景校正三种工作方式,分别对低、中、高三个水平土壤六价铬标准物质进行了测定,结果表明,低含量的土壤样品用塞曼背景校正方式测定的结果更准确,...     

Rapid determination of hexavalent chromium in textiles by a novel ammonium pyrrolidine dithiocarbamate derivatization combined with UHPLC–MS/MS

Hexavalent chromium is mainly determined by traditional spectrophotometry, atomic absorption spectrometry, and ion chromatography methods. In the present work, a reliable ultra high performance liquid chromatography with tandem mass spectrometry method was firstly developed for the determination of hexavalent chromium in textiles. The sample was extracted by acetic acid/sodium acetate buffer solution and followed by derivatization with ammonium pyrrolidine dithiocarbamate. The resulting derivative product was extracted by ethyl acetate, separated on a C18 column, and detected through electrospray ionization source in the positive mode with multiple reaction monitoring conditions. The derivatization reaction conditions were investigated and optimized. The developed method was validated in terms of the sensitivity, linearity range, matrix effects, recovery, accuracy, intra‐ and interday precision. Results showed that the calibration curves of pure solvent and matrix were linear over the selected concentration ranges of 0.1–20.0 μg/L. The achieved instrument and method limit of quantification were 0.1 and 40.0 μg/kg, respectively. Recoveries were calculated at three spiked concentrations and the values were between 92.2 and 103% with relative standard deviation values of 2.7–4.9% for intra‐day precision and 6.1% for inter‐day precision. Successful analysis of hexavalent chromium in practical textiles indicated that there was hexavalent chromium contamination in textiles.     

大体积进样离子色谱法检测饮用水中六价铬

建立了离子色谱检测饮用水中的六价铬的分析方法。以AS23柱分离,20mmol／L NaOH为淋洗液,1．0mL／min流量,1mL大体积进样,电导检测。结果表明,方法检测限为0．8μg／L,水样加标回收率在96．0％-102．0％之间,相对标准偏差为4．09％-1．40％;与标准方法二苯碳酰二肼分光光度法结果比对表明,该法检测限低、操作简便、准确快捷,适用于饮用水中六价铬的检测。     

Determination of total chromium in phosphate rocks by ion chromatography

Chromium(VI) is one of seven elements which is classified in the fertilizer industry as being harmful to plants and biological systems. Phosphate rocks represent the raw material for complex fertilizer production in the world. This paper investigates for the first time the determination of total chromium in phosphate rocks by ion chromatography. The developed analytical method involves the digestion of phosphate rocks with nitric acid followed by sample treatment of the resulting solution. The digestion solution obtained was treated with an oxidising agent (potassium peroxosulphate) to convert all chromium to the hexavalent state. The analytical method developed utilizes anion-exchange ion chromatography to achieve the separation and spectrophotometric post-column reaction for detection with diphenylcarbazide. The relative standard of deviation from analytical data comparison of six different phosphate rocks with atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry techniques, and cross-analysis data against an internationally certified phosphate rock standard were between 0.58 and 1.45%. Calibration curve between 0.2 and 0.9 μg/ml was excellent, and the method has a detection limit for Cr(VI) of 0.05 ng. The developed method offers a fast, a reliable and an alternative procedure for the determination of total chromium in phosphate rock deposits by ion chromatography.     

Determination of Chromium (VI) in Airborne Particulate Matter by Electrothermal Atomic Absorption Spectrometry

Hexavalent chromium Cr(VI) is a well-established carcinogen associated with lung, nasal, and sinus cancer. Cr(VI) threshold limit values in workroom air have been recently lowered. Consequently, the currently available analytical methods are insufficiently sensitive or high cost. In this paper, a simple, cost-effective, sensitive, and reproducible method using solid-phase extraction with electrothermal atomic absorption spectrometry for determination of hexavalent chromium in airborne samples is reported. The method validation included selectivity, linearity, accuracy, and precision. Interferences from other ions likely to be present in airborne samples, including trivalent chromium, were tested and selectivity was demonstrated. The detection and quantification limits were, respectively, as low as 0.1 and 0.4?µg?L^?1. The linearity ranged from 0.5 to 50.0?µg?L^?1, with a regression coefficients exceeding 0.998. The extraction recovery exceeded 98%. The developed method was successfully compared with a reference spectrophotometric method. The performances achieved were similar to ion chromatography and high-performance liquid chromatography approaches. The novel method was tested on airborne samples collected from the workplace. The method’s performance suggests that it may be an alternative to high-cost techniques for monitoring occupational exposure to hexavalent chromium.     

Determination of thallium in soils by flame atomic absorption spectrometry

A method is described for the determination of Tl in soils by FAAS, involving extraction of Tl from 5 g of soil by digestion with HClO₄/HNO₃ followed by separation of the extracted Tl into 5 mL of diisopropylether from HBr solution, including Ce(SO₄)₂. Tl in the organic phase is determined by direct aspiration into the spectrophotometer. The percentage relative standard deviation (% RSD) for 5 replicate samples is about 1%. The detection limits (S/N = 3) of this method are 0.001 mg/L for aqueous solution and 0.02 mg/kg DW for soil, when 50 mL of soil solution corresponding to 2.5 g soil are used. The Tl concentration even of unpolluted soils can be determined. The method was shown to be unaffected by the presence of various ions in soil and was able to recover nearly 100% Tl added to soils. The arithmetic mean (range) of 18 Japanese unpolluted surface soils was 0.33 (0.10–0.56)mgTl/kg DW.     

Optimization of a new resin, Amberlyst 36, as a solid-phase extractor and determination of copper(II) in drinking water and tea samples by flame atomic absorption spectrometry

A new simple and reliable method has been developed to separate and preconcentrate trace copper ion in drinking water and tea samples for subsequent measurement by flame atomic absorption spectrometry (FAAS). The copper ions are adsorbed quantitatively during passage of aqueous solutions through Amberlyst 36 cation exchange resin. After the separation and preconcentration stage, the analyte was eluted with a potassium cyanide solution and determined by FAAS. Different factors including pH of sample solution, sample volume, amount of resin, flow rate of aqueous solution, volume and concentration of eluent, and matrix effects for preconcentration were examined. The analytical figures of merit for the determination of copper are as follows: analytical detection limit (3 sigma), 0.26 microg/L; precision (RSD), 3.1% for 100 microg/L; enrichment factor, 200 (using 1000 mL of sample solution and 5 mL of eluent); time of analysis, 3.5 h (for obtaining enrichment factor of 200); capacity of resin, 125 mg/g. The method was applied for copper determination by FAAS in tap water, commercial natural spring water, commercial treated drinking water, and commercial tea bag sample. The accuracy of the method is confirmed by analyzing tea leaves (GBW 07605). The results demonstrated good agreement with the certified values.     

微波消解-原子吸收光谱法测定橡胶及其制品中镉

建立了橡胶及其制品中镉含量的快速测定方法. 样品采用微波消解, 消解溶液中的镉用火焰原子吸收光谱法测定. 方法的检出限为2.5 mg/kg, 多种代表性橡胶及其制品的镉元素回收率在101.6%～104.4%之间. 对某含镉橡胶样品的10个实验室3次平行测定的结果表明实验室内和实验室间的相对标准偏差分别1.8%和8.2%. 方法适用于各种橡胶材料中镉的快速分析.     

微波消解-电感耦合等离子体质谱(ICP-MS)法同时测定土壤中11种金属元素

称取0.25g样品加入5 mL硝酸和2 mL氢氟酸,用微波消解技术对样品进行前处理.以Re作为As、Pb、Tl的内标,Rh作为Cd、Co、Cr、Ni的内标,Bi作为Be、Cu、Zn的内标,Tb作为V的内标,建立了KED模式下微波消解电感耦合等离子体质谱(ICP-MS)法同时测定土壤中Be、As、Cd、Co、Cr、Cu、...     

Determination of dissolved hexavalent chromium in industrial wastewater effluents by ion chromatography and post-column derivatization with diphenylcarbazide

A proposed EPA method for the determination of dissolved hexavalent chromium in drinking water, groundwater and industrial wastewater effluents was developed using existing ion chromatographic techniques. Two solid waste matrices were briefly investigated. Aqueous samples were passed through a 0.45-micron filter and the filtrate was either (1) left unadjusted, (2) adjusted to pH 8 or (3) adjusted to pH 10 prior to analysis by ion chromatography. The method detection limits were 0.3-0.4 micrograms/l. When analyzed within 24 h, the two pH levels and the unadjusted sample yielded ca. 100% recovery of spikes. No oxidation of trivalent chromium to hexavalent chromium was observed at pH 7, 8 or 10 when aqueous samples were spiked with 50 mg/l Cr(III).