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排序方式: 共有29条查询结果,搜索用时 62 毫秒
1.
土壤重金属监测过程及其质量控制   总被引:10,自引:8,他引:2  
重点探讨了土壤中典型重金属含量监测过程中样品制备、含水率、预处理等因素对分析结果的影响。实验结果表明,充分风干土壤的含水率在2%~3%左右,200目土壤颗粒度可满足分析精度的要求。硝酸-氢氟酸-高氯酸的多元混酸消解体系可实现对土壤重金属的充分溶解,对标准土壤样品中各元素的回收率可达84%~98%。批次内平行样品以及批次间质控样品各元素的相对标准偏差大都小于10%,符合《土壤环境监测技术规范》的要求,表明该研究建立的系统土壤重金属检测方法结果准确可靠。  相似文献
2.
土壤介质中酞酸酯类污染物分析方法研究   总被引:3,自引:2,他引:1  
介绍了加压流体提取(PFL、ASE)提取-GPC净化-GC/MS分析土壤中酞酸酯类污染物方法的程序和质控要求,研究了每个步骤对分析六种目标物准确度和精密度的影响以及测定实际土壤样品的情况.结果显示,加压流体提取(PFL)、浓缩和GPC净化各步骤全程序空白加标回收率分别在86.3%~108%、78.5%~117%和87.4%~103%范围,精密度均在15%以内.在实际土壤样品中加入六种酞酸酯标准的加标回收率在45.2%~103.4%范围内,其相对标准偏差8%~23%.  相似文献
3.
“精密度偏性分析”是环境监测质量保证的重要手段   总被引:1,自引:0,他引:1  
“精密度偏性分析”是环境监测质量保证的重要手段。通过它可以了解其方法的误差和检出限是否达到要求,同时也了解实验室和操作人员对该方法的适应性。  相似文献
4.
用电感耦合等离子体原子发射光谱法测定水中Ba、Be、B、V、Co、Ti、Mo 7种元素含量,具有测定方法简便、快速、准确、精密度高、数据可靠等特点。  相似文献
5.
美国环境空气监测数据质量核查工作的经验与启示   总被引:1,自引:1,他引:0  
国控网城市环境空气自动监测点位的监测事权上收后,对监测数据精密度和准确度的定量化评价已成为考核运维公司工作成果、评估国控网数据质量、编制数据质量报告的迫切需求。为加强中国环境空气数据质量核查体系的建设,总结了美国环境空气监测数据质量核查体系及其相关的技术规范,简要介绍其包含的各类核查项目和主要特点,提出了建设中国环境空气数据质量核查体系的建议。  相似文献
6.
水中硝酸盐氮的2种测定方法比较   总被引:1,自引:0,他引:1  
对水中硝酸盐氮的2种测定方法进行了比较.结果表明,用离子选择电极法测定水中硝酸盐氮,准确度、精密度、抗干扰性均高于酚二磺酸分光光度法.所测结果经统计学处理,2种方法无显著性差异.离子选择电极法回收率为97.0%~102.0%.除氯离子、亚硝酸根离子外,不出现其它具有干扰意义水平的离子.  相似文献
7.
精密度--偏性分析质控试验数据处理系统   总被引:1,自引:1,他引:0  
杨洪泽  文朝阳 《干旱环境监测》2001,15(2):111-114,125
结合环境监测实验实质量控制数据处理的实际要求,用计算机高级语言,设计开发成功了《精密度-偏性分析质控试验数据处理系统》,该系统具有数据输入,查询,修改,统计分析和打印报告等功能,在实际应用中,取得良好效果。  相似文献
8.
Precision estimates are presented for precipitation chemistry and depth measurements made by the Canadian Air and Precipitation Monitoring Network (CAPMoN). The estimates were made for daily measurements of ion concentration and precipitation depth as well as for weekly, 28-day, seasonal and annual precipitation-weighted mean concentrations and depths. The data on which the estimates are based were collected from collocated samplers at five CAPMoN sites during the period 1985 to 1993. The data pairs from the collocated samplers were used to calculate the between-instrument error defined as 1/2 times the difference between the paired sample concentrations (or depths). For all of the ion concentrations and depths, the between-sampler errors were found not to be normally distributed, but the normality of the distributions improved with the length of the (volume-weighting) time period considered. A set of quantitative measures of overall network precision were derived in absolute (mg L-1) and relative (%) units. These included the Modified Median Absolute Deviation (M.MAD), the P90% probability values and the Coefficient of Variation (CoV). The latter, defined as the percent ratio of the M.MAD to the median concentration (or depth), represents the relative precision at the center of the error and concentration (and depth) distributions. Based on the CoV values, the relative precision of the CAPMoN measurements was very high (better than 4%) for SO 4 2- , NO 3 - , pH, H+, NH 4 + , sample depth and standard gauge depth, and not as high (between 10 and <35%) for Cl-, Na+, Ca2+, Mg2+, and K+. The ions with the lowest median concentrations had the poorest relative precision since so many of the concentrations were at or near the analytical detection limit. Except for the sample and standard gauge depths, both the absolute and relative precision improved with the length of the precipitation-weighting period. Detailed statistical testing established that the precision of the daily measurements is dependent on a number of factors, the most dominant being sample depth and concentration, i.e., the absolute precision improves with increasing sample depth and decreasing concentration. The strength of these relationships diminished with the length of the precipitation-weighting period being considered. Laboratory-related sources of imprecision were found to account for less than 4% of the overall daily measurement imprecision for most species, while field-related sources of imprecision accounted for the balance. Specialized plots are shown which allow data users to estimate the absolute and relative precision at any concentration and depth value.  相似文献
9.
Precision estimates are presented for precipitation chemistry and depth measurements made by the Canadian Air and Precipitation Monitoring Network (CAPMoN). The estimates were made for daily measurements of ion concentration and precipitation depth as well as for weekly, 28-day, seasonal and annual precipitation-weighted mean concentrations and depths. The data on which the estimates are based were collected from collocated samplers at five CAPMoN sites during the period 1985 to 1993. The data pairs from the collocated samplers were used to calculate the between-instrument error defined as 1/2 times the difference between the paired sample concentrations (or depths). For all of the ion concentrations and depths, the between-sampler errors were found not to be normally distributed, but the normality of the distributions improved with the length of the (volume-weighting) time period considered. A set of quantitative measures of overall network precision were derived in absolute (mg L-1) and relative (%) units. These included the Modified Median Absolute Deviation (M.MAD), the P90% probability values and the Coefficient of Variation (CoV). The latter, defined as the percent ratio of the M.MAD to the median concentration (or depth), represents the relative precision at the center of the error and concentration (and depth) distributions. Based on the CoV values, the relative precision of the CAPMoN measurements was very high (better than 4%) for SO 4 2- , NO 3 - , pH, H+, NH 4 + , sample depth and standard gauge depth, and not as high (between 10 and <35%) for Cl-, Na+, Ca2+, Mg2+, and K+. The ions with the lowest median concentrations had the poorest relative precision since so many of the concentrations were at or near the analytical detection limit. Except for the sample and standard gauge depths, both the absolute and relative precision improved with the length of the precipitation-weighting period. Detailed statistical testing established that the precision of the daily measurements is dependent on a number of factors, the most dominant being sample depth and concentration, i.e., the absolute precision improves with increasing sample depth and decreasing concentration. The strength of these relationships diminished with the length of the precipitation-weighting period being considered. Laboratory-related sources of imprecision were found to account for less than 4% of the overall daily measurement imprecision for most species, while field-related sources of imprecision accounted for the balance. Specialized plots are shown which allow data users to estimate the absolute and relative precision at any concentration and depth value.  相似文献
10.
GM100C动压平衡自动跟踪烟尘采样仪,跟踪精度高,响应时间快,无需换孔板,只要拨动波段开关就可换采样嘴。  相似文献
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