从能力验证结果看我国土壤重金属元素检测情况

根据2013—2018年期间土壤重金属元素(Ni、Cu、Zn、Pb、Cd、Cr、Hg、As)检测能力验证项目实验室参与情况,对各重金属元素检测的评价结果及采用的标准和检测方法进行了综合比较,分析了我国土壤中重金属检测的水平和发展趋势。结果表明,2013—2018年,我国土壤重金属检测实验室的检测水平逐年提高,参与能力验证的评价结果不满意率从2013年的8.6%降到了2018年的3.8%;获得认可的实验室能力验证平均满意率为92.9%,而非认可实验室平均满意率为88.3%;实验室检测所采用的标准以国家标准和环境标准为主,分别有57%和20%的实验室采用,其次是地矿、城建和农业等行业标准,国际标准的采用渐呈增长趋势,能达到4%。     

从能力验证结果看我国土壤重金属元素检测情况

根据2013—2018年期间土壤重金属元素(Ni、Cu、Zn、Pb、Cd、Cr、Hg、As)检测能力验证项目实验室参与情况,对各重金属元素检测的评价结果及采用的标准和检测方法进行了综合比较,分析了我国土壤中重金属检测的水平和发展趋势。结果表明,2013—2018年,我国土壤重金属检测实验室的检测水平逐年提高,参与能力验证的评价结果不满意率从2013年的8.6%降到了2018年的3.8%;获得认可的实验室能力验证平均满意率为92.9%,而非认可实验室平均满意率为88.3%;实验室检测所采用的标准以国家标准和环境标准为主,分别有57%和20%的实验室采用,其次是地矿、城建和农业等行业标准,国际标准的采用渐呈增长趋势,能达到4%。     

Acquisition of noise-induced hearing loss by railway workers

Lead-contaminated water, soil, and paint have been recognized as potential sources of children's lead exposure for decades, but their contributions to lead intake among urban children remain poorly defined. This analysis was undertaken to estimate the relationship of environmental lead exposures to lead intake among a random sample of urban children, adjusted for exposure to lead-contaminated house dust. Analyses of 183 urban children enrolled in a random sample, cross sectional study were conducted. Children's blood and multiple measures of household dust, water, soil, and paint were analyzed for lead, and interviews were conducted to ascertain risk factors for childhood lead exposure. Environmental sources of lead, including house-dust, soil lead, and water lead, were independently associated with children's blood lead levels. In contrast, paint lead levels did not have a significant effect on blood lead levels after adjusting for other environmental exposures. An increase in water lead concentration from background levels to 0.015 mg/L, the current EPA water lead standard, was associated with an increase of 13.7% in the percentage of children estimated to have a blood lead concentration exceeding 10 micrograms/dL; increasing soil lead concentration from background to 400 micrograms/g was estimated to produce an increase of 11.6% in the percentage of children estimated to have a blood lead level exceeding 10 micrograms/dL, and increasing dust lead loading from background to 200 micrograms/ft2 is estimated to produce an increase of 23.3% in the percentage of children estimated to have a blood lead level exceeding 10 micrograms/dL. These data support the promulgation of health-based standards for lead-contaminated dust and soil and the progressive lowering of standards for lead-contaminated water as the definition of undue lead exposure has been modified.     

Old paint removal and blood lead levels in children

AIM: To identify risk factors, particularly paint removal and clean up practices, for elevated blood lead levels in children, 12 to 24 months old, living in Wellington city. METHODS: Children living in residences more than 50 years old, where residential paint removal had taken place in the last two years, were recruited. Care givers were interviewed, a blood sample was taken from the child's arm and a dust wipe sample was collected from the kitchen floor. Blood and dust samples were analysed for lead content. RESULTS: Data were collected for 141 children (75% of those eligible). The mean blood lead level was 0.24 mumol/L (5.06 micrograms/dL). Higher blood levels were associated with lower income of the main family earner, playing outside, eating dirt and parental hobbies involving lead use. Children receiving regular medical treatment were at lower risk of lead absorption. With the exception of paint removal involving blow torches, none of the paint removal, clean up, or disposal practices was more strongly associated than the other methods with elevated blood lead levels in children living in the household. Dust wipes from the kitchen floor had little predictive value for blood lead level. CONCLUSIONS: High temperature methods of paint removal and parental hobbies involving lead are associated with higher lead levels in children. Given the availability of alternative means of paint removal, continuing use of high temperature methods is unnecessary. Further work is needed to assess lead absorption risks associated with hobbies involving lead.     

Source contribution of lead in house dust from a lead mining waste superfund site

The relative contribution to household dust of lead particles from a mining waste superfund site and lead-based paint is investigated. Automated individual particle analysis (IPA) based on scanning electron microscopy (SEM) and X-ray energy spectroscopy (EDX) is used to develop a classification algorithm for determining lead particle source contribution in household dust vacuum bags. On a volume basis the proportion derived from the mining waste is found to be 26%, the proportion derived from a paint source is 16%, and the proportion from soil is 37%. In 15% of the lead particles identified a specific originating source could not be determined. Using a weighting method accounting for the lead concentration per particle rather than volume the contributions were similar for mining waste and paint, 21% and 23%, respectively, but the soil contribution was reduced to 8%, and the source for 29% of the lead could not be identified. These results suggested that the contribution of waste piles to the lead present in household dust is at least as important a source as paint. There is evidence to suggest that a large percentage of lead in the soil also originated from the waste piles and the overall contribution, therefore, of the waste piles may be greater than the contribution from paint.     

ICP-AES法连续测定土壤样品中的铜、铅、锌、铁、锰

采用混酸溶解土壤样品,用ICP - AES法连续测定铜、铅、锌、铁、锰五种元素,对比了三种消解体系,优化了盐酸复溶体系,优化了仪器的使用条件,方法检出限为Cu 3.31 μg·g-1、Pb 8.95μg·g-1、Zn 4.22 μg·g-1、Fe 3.85μg·g-1、Mn4.15 μg·g-1.在加标回收实验中,相对标准偏差为2.81％ ～3.92％ (n=10),方法回收率为96.2％ ～ 104.0％.用于分析矿石样品,分析结果与推荐值相符,可用于地质实验室对大量矿石样品的检测.     

Material Control System for the Manufactured Housing Industry

A manufactured home is a factory-built house constructed in a controlled factory environment according to federal standards known as the Department of Housing and Urban Development (HUD) code. The manufactured home shares approximately 20% of the total housing units in the United States and plays an important role in providing affordable housing. However, in terms of material engineering, advanced techniques are scarcely used in the manufactured housing (MH) industry. The current material flow and control systems are characterized as independent demand systems that are based on the personal experience of the material managers. Although independent inventory control systems are widely used in many manufacturing industries, these systems lead to a large amount of inventory and have many drawbacks for the MH industry. On the other hand, dependent inventory systems can reduce unfavorable inventory levels using new techniques and present substantial benefits for the MH industry. This paper applies lean inventory control systems and supply chain management techniques to the current systems of the MH industry and proposes a new framework of material control systems as one of the system management tools.     

火焰原子吸收法连续测定土壤样品中的铜、铅、锌、钴、镍

采用王水溶解土壤样品,用火焰原子吸收法连续测定铜、铅、锌、钴、镍五种元素,对比了两种消解体系,优化了盐酸复溶体系,优化了仪器的使用条件,方法检出限为Cu 1.14μg.g-1、Pb 3.14μg.g-1、Zn 0.50μg.g-1、Co 0.94μg.g-1、Ni 1.10μg.g-1。在加标回收实验中,相对标准偏差为2.67%~4.04%(n=10),方法回收率为92.7%~107.3%。方法用于分析土壤样品,分析结果与推荐值相符,可用于地质实验室对大量土壤样品的检测。     

激光诱导击穿光谱法测定玩具油漆表面铅含量

采用家用铅检测试剂对编号为2579e的表面含铅油漆标样进行了定性测量,讨论了铅在玩具油漆表层中的深度分布,并建立了激光诱导击穿光谱法测定玩具油漆表面铅含量的方法。为减弱自吸收的影响,在铅405.78 nm谱线处,采用谱线强度(I)与铅浓度(c)关系的对数形式建立校准曲线。实验表明,线性方程为lgI=5.56+0.44·lgc,曲线的拟合度(R)为0.956,方法检出限为72 μg/g。采用方法对碳酸盐岩石成分分析标准物质GBW07136进行测定,结果与认定值的相对误差为8.3%,10次平行测定的相对标准偏差为7.1%。采用方法测得市购橘色玩具小车表面铅的含量是18.5 mg/g。     

Detection of lead in environmental objects and biologic materials during monitoring]

The authors specified methods to detect lead in biologic materials. The quality control covered use of Russian and foreign standard samples, the results proved to agree. Lead was detected by AAS technique (direct and flow-type variants with preliminary concentration of lead) and ELRA method. The authors determined measurement limits sufficient for analysis of complex biologic materials. The measurement range for lead varied from 0.002 mg/kg (plants) to 3,000 mg/kg (soil); the range of serum lead levels was < 0.5-39 mg/dl.     

Removal of Lead from Contaminated Water and Clay Soil Using a Biosurfactant

Lead removal from water and contaminated soils was investigated using biosurfactant, anionic, and nonionic surfactants in continuously stirred batch reactors. Lead-contaminated water up to 100?mg/L and clay soil up to 3,000?mg/kg were used in this investigation. The surfactant concentration up to 10 critical micelle concentration was used. The speciation of lead into the micelles was quantified and the lead removal efficiency depended on the level of contamination, surfactant type, and concentration. Of the surfactants used, biosurfactant (produced from used vegetable oil) had the best removal efficiency (75%) at a lead contamination of 100?mg/L in water at pH of over 12. The Fourier-transformed infrared spectroscopy study showed that the carboxyl group in the biosurfactant was effective in removing the lead from the solution. Langmuir and Freundlich relationships were used to represent the micelle partitioning of lead in the surfactant solutions. Desorption of lead from contaminated kaolinite clay was represented using linear isotherms. The biosurfactant solution had a higher micelle partitioning for the lead from contaminated water and desorbing the lead from the contaminated soil compared to the other chemical surfactants.     

Determination of calcium by inductively coupled plasma-atomic emission spectrometry, and lead by graphite furnace atomic absorption spectrometry, in calcium supplements after microwave dissolution or dry-ash digestion: method trial

A 3-laboratory method trial was conducted to evaluate 2 sample digestion procedures and instrumental determination parameters for analysis of calcium and lead in Ca supplements. Calcium supplements were treated by dry-ash digestion or microwave dissolution prior to spectrometric analysis. In each case, Pb was determined by graphite furnace atomic absorption spectrometry and Ca by inductively coupled plasma-atomic emission spectrometry. Blind duplicates of 6 Ca supplement samples were analyzed after each sample treatment procedure. Matrix pairs contained dissimilar Pb levels to cover the analyte range encountered during method development. Calcium content of the Ca supplement samples also reflected the range seen during method development. Stock solutions of Ca and Pb were supplied to collaborators for preparation of quantitation standards to remove a variable external to the method. National Institute of Standards and Technology Standard Reference Material (NIST SRM) 1486, bone meal, was included to assess method accuracy and recovery at NIST certificate Ca and Pb levels for this material (26.58 +/- 0.24% Ca and 1.335 +/- 0.014 micrograms Pb/g). Analyses of the NIST SRM yielded 25.9 +/- 1.1 and 27.2 +/- 2.3% Ca and 1.53 +/- 0.19 and 1.26 +/- 0.19 micrograms Pb/g for dry-ash and microwave procedures, respectively. Statistical analyses of data indicated acceptable repeatability and reproducibility for determination of Pb and Ca in various Ca supplements. With either sample preparation technique, the method is appropriate for determining Pb or Ca in Ca supplements.     

Increased lead absorption with anemia and slowed nerve conduction in children near a lead smelter

Studies to evaluate the prevalence, sources, and health consequences of lead absorption were conducted among children living near a primary lead smelter. Lead levels in air, soil, and dust were highest at the smelter and decreased with distance. Ninety-nine percent of one- to nine-year-old children living within 1.6 kilometers had blood lead levels greater than or equal 40 mug/dl, indicating increased absorption, and 22% had levels greater than or equal 80 mug/dl. The prevalence of lead levels greater than or equal 40 mug/dl decreased with distance; at 72 kilometers from the smelter it was 1%. Erythrocyte protoporphyrin levels increased with blood lead levels: 17% of children with lead levels of greater than or equal 80 mug/dl were anemic. There was no overt neurologic toxicity. Significant negative correlation was found in 202 five- to nine-year-old children between blood lead levels and motor nerve conduction velocity (r = 0.38, p less than 0.02).     

Prevailing conditions and problems with blood transfusion tests as seen after analysis of Osaka Medical Association Survey

We have analysed the results of the 1996 Osaka Medical Association Clinical Examination Quality Control survey. The number of participating clinical laboratories was 257 for ABO blood group system, 255 for Rh (D) antigen, and 250 for crossmatching. Five (5) clinical laboratories (1.9%) determined the ABO blood group by the antigens on red blood cells test only, and three (3) clinical laboratories (1.2%) showed errors when using antibodies in serum test. On the Rh(D) antigen tests, fifteen (15) clinical laboratories (5.9%) showed negative results without carrying out an antiglobulin test. Three (3) clinical laboratories (1.2%) were unable to detect the anti Dib antibody which showed 1:256 titerates using the antiglobulin test method. Moreover, it was apparent that thirty-four (34) clinical laboratories (13.6%) had problems with the test standards and other technical points, and further, two (2) clinical laboratories (0.8%) reported contradictory results due to confusing blood samples of donors and patients to be transfused. As a result, we consider it very important for preventing blood transfusion accidents that any technician carrying out blood transfusion tests makes correct decisions and determinations based on accurately performed test methods, and that a manual be prepared to avoid technical and administrative errors and that this manual be followed to the letter.     

微波消解-电感耦合等离子体质谱法测定煤炭中铅镉铬砷汞铍

将微波消解技术与电感耦合等离子体质谱法相结合测定了煤炭中铅、镉、铬、砷、汞、铍6种元素。以硝酸和氢氟酸作为消解试剂,采用高压密闭微波消解仪及功率控制梯度消解模式,在190 ℃温度、38 bar压力,0.3 bar/s升压速率的条件下消解样品。样品消解完全后加入一定量硼酸,除去过量的氢氟酸以保护仪器。测定时,选择²⁰²Hg、²⁰⁸Pb 、⁹Be、⁷⁵As、⁵³Cr和¹¹⁴Cd作为测定同位素,同量异位素的干扰采用无干扰元素校正方式来消除,基体效应产生的信号漂移采用¹⁰³Rh作为内标进行校正。方法应用于SARM 19煤和GBW07430土壤有证标准物质的分析,测定值与认定值吻合,相对标准偏差(RSD,n=8)在1.5%～5.6%范围,回收率在88%～110%之间。     

模拟大气颗粒物混合元素滤膜标准样品的研制与质量考察

用能量色散X射线荧光光谱法(ED-XRF)测定大气颗粒物滤膜样品中Na、Mg、Al、Si、P、S、Cl、K、Ca、Ti、V、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Pb、Sr、Ba等无机元素的HJ 829—2017标准已颁布实施多年。颗粒物滤膜标准样品对于校准曲线的建立、评估具有重要意义。目前市场仅有美国NIST SRM 2783一种模拟大气颗粒物滤膜标准样品,价格昂贵,基层实验室在日常检测工作中很难用于质控工作。没有价格合适、质量符合要求相关产品投放市场,基层实验室大气颗粒物元素XRF分析质控工作就无法落实。借鉴国外模拟大气颗粒物滤膜标样制备方法,以湖南污染土壤标样为加工原材料,经进一步粉碎后,利用表面活性剂将细颗粒物制成悬浊液,定量、均匀分布在多孔滤膜上。6家ED-XRF实验室,1家质子激发X荧光光谱分析(PIXE)和1家中子活化分析(NAA)实验室,对同批次制备的120张滤膜样品随机抽取14张进行了测试,对滤膜上20多种元素测定结果的准确度和精密度进行了评估。初步分析结果表明:Al、Fe、Zn、As、Ba、Ti、Pb等元素含量与依据土壤标样元素认定值比值推算的结果基本相符;Al、Si、Fe、Ti、Mn、Zn、K、As、Pb等元素含量相对标准偏差(RSD)范围为6.8%~21%,基本满足滤膜质控样品要求,可以提供给基层实验室试用。提出了后续研究工作思路及计划。     

基体稀释或基体匹配石墨炉原子吸收光谱法测定土壤样品中铅和镉

用石墨炉原子吸收光谱法测定土壤样品中Pb和Cd时,有时候直接按照方法标准GB/T 17141—1997操作,测定结果不能满足质控要求。研究结果表明,目标元素系列标准溶液中,分别含和不含土壤基体元素Na、Mg、Al、Si、Fe、Ca等元素混合成分时,校准曲线斜率明显不同。为减小基体效应的影响,基于文献调研和实验结果,对上述方法标准实验步骤进行了下列改进:(1)取相同体积实际样品消解液混合后,定量加入到用于建立校准曲线的系列标准溶液中,用于基体匹配;(2)对消解液进行适度稀释,仍采用标准溶液建立校准曲线。用4个土壤标样和土壤样品加标测定结果对改进后的方法进行了验证,结果表明,基体稀释法测定Pb的回收率范围分别为90.4%~114%;测定低含量Cd时,回收率范围为84.1%~125%。基体匹配法测定Pb和Cd的回收率范围分别为93.0%~105%和102%~119%,基本满足土壤样品中重金属回收率为80%~120%的质控要求。样品中痕量镉在测定下限附近时,应严格控制稀释倍数,或采用基体匹配法测定。改进后的操作步骤适合日常检测工作中大批量土壤样品中Pb和Cd的准确测定。     

基体稀释或基体匹配石墨炉原子吸收光谱法测定土壤样品中铅和镉

用石墨炉原子吸收光谱法测定土壤样品中Pb和Cd时,有时候直接按照方法标准GB/T 17141—1997操作,测定结果不能满足质控要求。研究结果表明,目标元素系列标准溶液中,分别含和不含土壤基体元素Na、Mg、Al、Si、Fe、Ca等元素混合成分时,校准曲线斜率明显不同。为减小基体效应的影响,基于文献调研和实验结果,对上述方法标准实验步骤进行了下列改进:(1)取相同体积实际样品消解液混合后,定量加入到用于建立校准曲线的系列标准溶液中,用于基体匹配;(2)对消解液进行适度稀释,仍采用标准溶液建立校准曲线。用4个土壤标样和土壤样品加标测定结果对改进后的方法进行了验证,结果表明,基体稀释法测定Pb的回收率范围分别为90.4%~114%;测定低含量Cd时,回收率范围为84.1%~125%。基体匹配法测定Pb和Cd的回收率范围分别为93.0%~105%和102%~119%,基本满足土壤样品中重金属回收率为80%~120%的质控要求。样品中痕量镉在测定下限附近时,应严格控制稀释倍数,或采用基体匹配法测定。改进后的操作步骤适合日常检测工作中大批量土壤样品中Pb和Cd的准确测定。     

电感耦合等离子体质谱法测定地球化学样品中铌钽钨锡

采用HCl-HNO3-HF-HClO4溶解地球化学样品,以50 mg/L酒石酸-1％ HCl为测定介质克服了铌、钽、钨、锡易水解的特性,选择93 Nb、181 Ta、182W、118Sn为分析同位素及50 ng/mL185Re为内标,建立了电感耦合等离子体质谱法(ICP-MS)同时测定地球化学样品中微量铌、钽、钨、锡的...     

Zebrafish visual sensitivity is regulated by a circadian clock

Carbonaceous aerosols are present in many workplace and environmental settings. Some of these aerosols are known or suspect human carcinogens and have been linked to other adverse health effects. Exposure to diesel exhaust is of particular concern because it has been classified as a probable human carcinogen and use of diesel-powered equipment is widespread in industry. Because previously used methods for monitoring exposures to particulate diesel exhaust lack adequate sensitivity and selectivity, a new method was needed. A carbon analysis technique called the thermal-optical method was evaluated for this purpose. In thermal-optical analysis, carbon in a filter sample is speciated as organic and elemental (OC and EC, respectively). When the thermal-optical method was initially evaluated, only one instrument was available, so interlaboratory variability could not be examined. More recently, additional instruments were constructed and an interlaboratory comparison was completed. Eleven laboratories participated in the study, including four in Europe that employ an alternative thermal technique based on coulometric detection of CO2. Good agreement (RSDs less than or equal to 15%) between the total carbon results reported by all laboratories was obtained. Reasonable within-method agreement was seen for EC results, but the EC content found by the two methods was differed significantly. Disagreement between th OC-EC results found by the two methods was expected because organic and elemental carbon are operationally defined. With all filter samples, results obtained with the coulometric method were positively biased relative to thermal-optical results. In addition, the alternative method gave a positive bias in the analysis of two OC standard solutions. About 52% and 70% of the carbon found in two aqueous solutions containing OC only (sucrose and EDTA, respectively) was quantified as elemental,while EC contents of about 1% and 0.1% (respectively) were found by the thermal-optical method. The positive bias in the analysis of the OC standards is attributed largely to inadequate removal of OC during the first part of the analysis; lack of correlation for pyrolytically formed carbon (char) also is a factor. Results obtained with a different thermal program having a higher maximum temperature were in better agreement with the thermal-optical method.