氢化物发生-原子荧光光谱法测定铬矿中铅

建立了一种过氧化钠熔融、盐酸酸化提取,氢化物发生-原子荧光光谱法定量测定铬矿中铅的方法。试验优化了样品熔样温度、熔样时间、熔剂用量及上机测试条件,检验了共存元素的干扰。实验结果表明,方法精密度(RSD, n=11)为1.47%～3.68%,加标回收率为96%~105%,检出限为0.2μg/g。方法用于铬矿中元素铅的测定,精密度高、准确性好,检出限低,满足铬矿中铅元素的定量检测要求。     

酸化吹气-重铬酸钾法测定高氯地表水中化学需氧量方法适用性研究

为研究酸化吹气-重铬酸钾法测定高氯地表水中化学需氧量的适用性,6家实验室使用酸化吹气-重铬酸钾法对高氯地表水中化学需氧量进行测定。结果表明,该方法的检出限为4mg/L,6家实验室对3种浓度的标准溶液(氯化物浓度均为2万mg/L)进行精密度测试,实验室内相对标准偏差范围分别为3.4%～9.6%、2.9%～4.4%、1.7%～7.5%,实验室间相对标准偏差分别为3.2%、2.3%、3.4%;对2个不同浓度的高氯地表水实际样品进行精密度测试,实验室内相对标准偏差范围为2.7%~5.7%、2.1~7.5%,实验室间相对标准偏差分别为4.1%、13.4%;对3种浓度的标准溶液(氯化物浓度均为2万mg/L)进行准确度测试,实验室内相对标准偏差范围为-1.0%～11.0%、-3.0%～3.5%、-5.3%～4.0%,室间相对误差的标准偏差分别为4.0%、2.3%、3.4%。方法去除氯离子干扰效果好,精密度、准确度及检出限较好,适用于高氯地表水中化学需氧量的测定。     

应用二极管阵列串联荧光检测-高效液相色谱技术快速测定玩具材料中蒽油的4种成分

采用二极管阵列串联荧光检测-高效液相色谱法对玩具材料中蒽油的4种主要成分蒽、菲、芘、荧蒽进行了检测。样品用正己烷-丙酮溶液超声提取,硅胶小柱净化。方法的荧光检测线性范围为0.5～1000 μg/L,二极管阵列检测线性范围为0.5～1000 mg/L。加标回收、精密度试验表明4种成分的回收率为70.0%～120%,精密度为0.7%～8.8%。蒽、菲、芘、荧蒽的检出限分别为0.1、0.1、0.2、0.3 μg/L,定量限分别为0.4、0.2、0.5、0.8 μg/L。方法具有灵敏度高、检出限低的特点,适用于玩具材料中蒽油4种成分的快速定性、定量检测。     

ICP-AES法同时测定树脂样品中的15种金属元素

研究建立了电感耦合等离子体发射光谱法(ICP-AES)同时测定离子交换树脂中Al、Ba、Ca、Co、Cr、Cu、Fe、K、Li、Mg、Mn、Na、Ni、Pb、Zn等15种金属元素的方法,进行了必要的条件试验,选择了分析谱线及其仪器工作参数;考察了无机酸的酸度对测定的影响;在优化条件下,进行了准确度和精密度试验,方法的回收率和精密度分别在87.1%～103.4%和0.5%～5.3%范围,该方法各元素的检出限能满足实验要求,适合离子交换树脂中元素含量的常规分析.     

原子荧光光谱法同测粮食中砷汞总量的条件选择及干扰控制

通过优化原子荧光光谱仪的原子化高度、负高压、灯电流和载气流量等4个主要工作条件,并对仪器产生干扰的因素环境温度、光源稳定性、试剂进行研究,并用加标回收实验对方法的准确度进行验证,确定了原子荧光光谱法同时测定粮食中砷汞总量时的最优条件和有效的干扰控制方法。结果显示,在最优条件下,As的检出限为0.024 7ng/mL,相对标准偏差(RSD)为0.37%,线性相关系数r=0.999 9;Hg检出限为0.001 5ng/mL,相对标准偏差(RSD)为0.44%,线性相关系数r=0.999 9,仪器检测稳定性好,灵敏度高,各项指标均优于标准规定,且检测结果精密度高、准确性好。     

原子荧光光谱法同时测定粮食中砷汞总量的条件选择及干扰控制

通过优化原子荧光光谱仪的原子化高度、负高压、灯电流和载气流量等4个主要工作条件,并对仪器产生干扰的因素环境温度、光源稳定性、试剂进行研究,并用加标回收实验对方法的准确度进行验证,确定了原子荧光光谱法同时测定粮食中砷汞总量时的最优条件和有效的干扰控制方法。结果显示,在最优条件下,As的检出限为0.024 7ng/mL,相对标准偏差(RSD)为0.37%,线性相关系数r=0.999 9;Hg检出限为0.001 5ng/mL,相对标准偏差(RSD)为0.44%,线性相关系数r=0.999 9,仪器检测稳定性好,灵敏度高,各项指标均优于标准规定,且检测结果精密度高、准确性好。     

离子色谱用于标准物质硫酸根定值的方法研究

对离子色谱用于测定标准物质硫酸根定值的方法进行了研究。采用阴离子分析柱IonPac AS19(2 mm×250 mm),抑制型电导检测,进样体积25 μL,NaOH为等度淋洗液,通过正交设计表安排试验,确定了优化的色谱条件。SO2-4的检出限是0.005 mg/L,方法的精密度（RSD）为0.44%,方法的线性范围是1.0～50.0 mg/L, 样品的平均加标回收率为95.5%～105%。利用校正曲线的稳定性检查,质控样的可靠性检查和回收率试验证明该分析方法是可靠的。该方法操作简单、速度快、灵敏度高、重复性好,已用于标准物质硫酸根的定值。     

高频燃烧红外吸收法测定铅精矿中的硫

利用高频燃烧红外吸收碳硫仪测定铅精矿中的硫含量。低硫含量(S<5%)铅精矿样品直接称样测定;高硫含量(S>5%)铅精矿样品添加稀释剂后称样测定。对样品称样量、助熔剂类型及用量等条件进行了研究,获得最佳分析条件。通过空白实验测得方法检出限为0.0010%,利用铅精矿有证标准物质进行精密度和准确度验证,方法的标准偏差在0.295%~1.3%之间,结果表明该方法精密度高、准确度好,能够满足铅精矿中硫含量的快速准确测定。     

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。     

酸化吹气-重铬酸钾法测定高氯地表水中化学需氧量

为研究酸化吹气-重铬酸钾法测定高氯地表水中化学需氧量的适用性,6家实验室使用酸化吹气-重铬酸钾法对高氯地表水中化学需氧量进行测定。结果表明,方法的检出限为4mg/L,6家实验室对3种浓度的标准溶液(氯化物浓度均为20 000mg/L)进行精密度测定,实验室内相对标准偏差范围分别为3.4%～9.6%、2.9%～4.4%、1.7%～7.5%,实验室间相对标准偏差分别为3.2%、2.3%、3.4%;对2个不同浓度的高氯地表水实际样品进行精密度测定,实验室内相对标准偏差范围为2.7%～5.7%、2.1%～7.5%,实验室间相对标准偏差分别为4.1%、13.4%;对3种浓度的标准溶液(氯化物浓度均为20 000mg/L)进行准确度测定,实验室内相对标准偏差范围为-1.0%～11.0%、-3.0%～3.5%、-5.3%～4.0%,室间相对误差的标准偏差分别为4.0%、2.3%、3.4%。方法去除氯离子干扰效果好,精密度、准确度及检出限较好,适用于高氯地表水中化学需氧量的测定。     

电感耦合等离子体光谱法测定铜冶炼烟尘中锌

本实验介绍了电感耦合等离子体光谱法测定铜冶炼烟尘中锌含量的分析方法。针对样品碳,硅含量高的特点,有针对性的研究了样品的消解方法,确定采用盐酸、硝酸、氢氟酸、高氯酸对铜冶炼烟尘样品进行消解。同时进行了干扰试验,确定样品中高含量的铜,铅,砷等对样品测定结果没有影响。并对仪器的工作参数进行了优化。方法检出限为为0.011 mg/L,测定下限为0.019 mg/L,3个样品的相对标准偏差在0.54%~0.92%之间,加标回收率在96%~101.14%之间。该方法样品消解完全,流程短,操作简单,快速,测定准确度高,可以满足铜冶炼烟尘中锌含量的测定。     

电感耦合等离子体质谱法(ICP-MS)测定废水中有害元素银的含量

为了寻求一种更加适合废水中低含量银的测定方法,本文采用石墨电热板消解-电感耦合等离子体质谱法测定废水中的低含量银离子。通过仪器工作条件最优化、测定线性回归方程、检出限、准确度、精密度、实际样品加标回收率,并与电感耦合等离子体发射光谱法（ICP-AES）的实际样品测定结果进行比对来评价该方法的实用性。石墨电热板消解-电感耦合等离子体质谱法前处理方法简便,分析速度快且该方法检出限较低,为0.03ug/L,标准样品测定的相对误差为-0.7%～1.7%,相对标准偏差为1.1%～2.5%,实际样品加标回收率在97.0%～103%之间,回收率高,能够满足废水中低含量银的测定。     

Analysis of PCBs in soils and sediments by microwave-assisted extraction,headspace-SPME and high resolution gas chromatography with ion-trap tandem mass spectrometry

A procedure for the determination of seven indicator PCBs in soils and sediments using microwave-assisted extraction (MAE) and headspace solid-phase microextraction (HS-SPME) prior to GC-MS/MS is described. Optimization of the HS-SPME was carried out for the most important parameters such as extraction time, sample volume and temperature. The adopted methodology has reduced consumption of organic solvents and analysis runtime. Under the optimized conditions, the method detection limit ranged from 0.6 to 1?ng/g when 5?g of sample was extracted, the precision on real samples ranged from 4 to 21% and the recovery from 69 to 104%. The proposed method, which included the analysis of a certified reference material in its validation procedure, can be extended to several other PCBs and used in the monitoring of soil or sediments for the presence of PCBs.     

Quantitative determination of acidic hydrolysis products of Chemical Weapons Convention related chemicals from aqueous and soil samples using ion‐pair solid‐phase extraction and in situ butylation

Chemical warfare agents such as organophosphorus nerve agents, mustard agents, and psychotomimetic agent like 3‐quinuclidinylbenzilate degrade in the environment and form acidic degradation products, the analysis of which is difficult under normal analytical conditions. In the present work, a simultaneous extraction and derivatization method in which the analytes are butylated followed by gas chromatography and mass spectrometric identification of the analytes from aqueous and soil samples was carried out. The extraction was carried out using ion‐pair solid‐phase extraction with tetrabutylammonium hydroxide followed by gas chromatography with mass spectrometry in the electron ionization mode. Various parameters such as optimum concentration of the ion‐pair reagent, pH of the sample, extraction solvent, and type of ion‐pair reagent were optimized. The method was validated for various parameters such as linearity, accuracy, precision, and limit of detection and quantification. The method was observed to be linear from 1 to 1000 ng/mL range in selected ion monitoring mode. The extraction recoveries were in the range of 85–110% from the matrixes with the limit of quantification for alkyl phosphonic acids at 1 ng/mL, thiodiglycolic acid at 20 ng/mL, and benzilic acid at 50 ng/mL with intra‐ and interday precisions below 15%. The developed method was applied for the samples prepared in the scenario of challenging inspection.     

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。     

微波消解-电感耦合等离子体质谱(ICP-MS)法测定土壤七种金属元素

实验室比对盲样测定是检验实验室能力验证、实验室资质认定、机构考核的主要手段。为研究并解决测试实验室比对土壤盲样中铍、钒、镍、铜、锌、镉、铅的含量,采用微波消解电感耦合等离子体质谱(ICP-MS)法对土壤盲样进行研究,探讨了不同消解酸体系,检出限和定量限、测试模式和干扰消除、精密度和加标回收率、质控样品进行研究。结果表明：用6 mL HNO3,2 mL HCl和1 mL HF为混合酸体系,各待测元素标准曲线相关系数大于0.9995,检出限在0.001~2.985 mg.L-1^,定量限在0.003~9.94 mg.L-1^,采用氦气碰撞模式测试钒、镍、铜、锌、镉和铅,可以有效的降低多原子离子的干扰;采用no gas模式测试铍,可以有效的提高铍的测试灵敏度。方法精密度为0.2%~6.2%(n=6),加标回收率为92.3%~110.6%,采用土壤标准样品(GSS-4)进行全过程质控研究分析,各元素结果均在标准值参考范围内。用ICP-OES法测试土壤盲样中七种待测金属元素含量与用铑为内标的ICP-MS进行比对,测量分析结果基本一致。     

Automated sample treatment with the injection of large sample volumes for the determination of contaminants and metabolites in urine

This work reports the development of a simple and automated method for the quantitative determination of several contaminants (triazine, phenylurea, and phenoxyacid herbicides; carbamate insecticides and industrial chemicals) and their metabolites in human urine with a simplified sample treatment. The method is based on the online coupling of an extraction column with RP LC separation–UV detection; this coupling enabled fast online cleanup of the urine samples, efficiently eliminating matrix components and providing appropriate selectivity for the determination of such compounds. The variables affecting the automated method were optimized: sorbent type, washing solvent and time, and the sample volume injected. The optimized sample treatment reported here allowed the direct injection of large volumes of urine (1500 μL) into the online system as a way to improve the sensitivity of the method; limits of detection in the 1–10 ng/mL range were achieved for an injected volume of 1500 μL of urine, precision being 10% or better at a concentration level of 20 ng/mL. The online configuration proposed has advantages such as automation (all the steps involved in the analysis – injection of the urine, sample cleanup, analyte enrichment, separation and detection – are carried out automatically) with high precision and sensitivity, reducing manual sample manipulation to freezing and sample filtration.     

Determination of myristicin in rat serum samples using microbore high performance liquid chromatography with column-switching

Summary A microbore high-performance liquid chromatographic method with column-switching was developed for the analysis of myristicin from rat serum without prepurification. Deproteinization, fractionation, concentration and separation of analyte were carried out by appropriate switching of columns and using solvent mixtures. The method showed excellent precision, accuracy and speed with a detection limit of 10 ng mL⁻¹ from 25 μL of serum. The total analysis time per sample was 25 min and the coefficients of variation for intra- and inter-assay were less than 1.8%.     

An Alternative Strategy for Screening and Confirmation of 330 Pesticides in Ground- and Surface Water Using Liquid Chromatography Tandem Mass Spectrometry

The presence of pesticide residues in water is a huge worldwide concern. In this paper we described the development and validation of a new liquid chromatography tandem mass spectrometric (LC-MS/MS) method for both screening and quantification of pesticides in water samples. In the sample preparation stage, the samples were buffered to pH 7.0 and pre-concentrated on polymeric-based cartridges via solid-phase extraction (SPE). Highly sensitive detection was carried out with mobile phases containing only 5 mM ammonium formate (pH of 6.8) as an eluent additive and using only positive ionization mode in MS/MS instrument. Hence, only 200-fold sample enrichment was required to set a screening detection limit (SDL) and reporting limit (RL) of 10 ng/L. The confirmatory method was validated at 10 and 100 ng/L spiking levels. The apparent recoveries obtained from the matrix-matched calibration (5–500 ng/L) were within the acceptable range (60–120%), also the precision (relative standard deviation, RSD) was not higher than 20%. During the development, 480 pesticides were tested and 330 compounds fulfilled the requirements of validation. The method was successfully applied to proficiency test samples to evaluate its accuracy. Moreover, the method robustness test was carried out using higher sample volume (500 mL) followed by automated SPE enrichment. Finally, the method was used to analyze 20 real samples, in which some compounds were detected around 10 ng/L, but never exceeded the assay maximum level.