国控重点污染源监督监测数据QA/QC量化评估体系探讨

阐述了建立国控重点污染源监督监测数据质量QA/QC量化评估体系的重要性和迫切性,从国控污染源QA/QC量化评估体系建设的基本思路、量化评估指标的组成、量化评估指标的权重及QL阈值等方面,对国控重点污染源监督监测数据质量QA/QC量化评价体系的建立进行探讨。     

水环境应急快速监测QA/QC技术体系探讨

针对目前国家缺乏应急监测质量管理相关技术规定情况,重点研究了水环境应急监测的QA/QC技术,通过对应急备战状态和应急实战状态两大环节9个要素的操作层面的探讨,初步形成了一套较为系统实用的水环境应急监测的QA/QC技术体系.     

浅谈我国水质自动监测质量保证与质量控制

文章阐述了水质自动监测全过程的质量保证与质量控制措施,包括站点选择、采配水单元设计、仪器选型及日常监测等,并根据实际经验,对自动监测数据质量检查和审核提出了建议。     

离子选择电极法测定水中氟化物质量控制指标研究

通过全国多家实验室的大量监测数据,研究分析了离子选择电极法测定水中氟化物的质量控制指标。研究表明,在0.5～4.5 mg/L范围内同一标准样品多次测定的质量控制指标为:室内相对标准偏差(RSD)≤4.0%,室间相对标准偏差(RSD’)≤8.0%,相对误差(RE)≤±10.0%。在0.06～7.0 mg/L范围内实际样品平行双样测定质量控制指标为:相对偏差(RD)≤5.0%。加标回收率范围为90%～110%。     

瓦里关气相色谱法大气CO_2和CH_4在线观测数据处理分析

加强我国本底站温室气体数据资源的科学管理与共享,首先应保证观测全流程的标准化和规范化,确立数据处理和质量控制方法.我国青海瓦里关全球本底站自1994年开始了气相色谱-氢火焰离子化检测器法(GC-FID)大气CO2和CH4在线观测,本文详细讨论了该系统原始资料采集、数据信息合并、时间序列检查、观测员级质量控制和专家级质量控制等流程.利用局部近似回归法对大气CO2和CH4数据进行本底值筛分,获得CO2本底数据百分比约占有效数据的72%、CH4占44%.在线观测的CO2和CH4月平均浓度与同期瓶采样分析结果基本一致,相对偏差均在±0.5%以内.经流程化处理和质控的瓦里关大气CO2和CH4本底浓度变化资料已进入全球同化数据库(Globalview-CO2、Globalview-CH4),报送世界温室气体数据中心(WDCGG)并应用于世界气象组织(WMO)温室气体公报和联合国政府间气候变化专门委员会(IPCC)评估.     

城市污水中PCBs的分析及其QA/QC研究

报道了一种城市污水中痕量PCBs的分析方法,并进行了QA/QC研究,采用二氯甲烷萃取剂对城市污水进行液-液萃取,联合运用浓硫酸和硅胶层析柱将PCBs与杂质分离,以毛细管GC-ECD和内标法对PCBs定量.空白加标回收试验得出,PCBs的回收率为58%～125%,标准偏差为0.00173～0.00778μg/L,相对标准偏差为1.58%～12.43%.以实际城市污水作为加标基质,得出加入污水中的19种PCBs的分析方法回收率为57.6%～129.2%,方法的检测限为0.010～0.056μg/L,满足了US EPA对PCBs回收率要求.经过3次平行测定,测得实际城市污水中PCBs含有9种PCBs,PCBs总量的平均值为0.0235μg/L,相对标准偏差为9.63%,该分析方法所需的仪器简便、容易操作.     

标准样品在环境监测应用中几点问题的探讨

环境(有证)标准样品(CERM)已成为环境监测及其质量保证/质量控制(QA/QC)重要工具和常用方法,科学理解和合理使用CERM越来越重要。 文章将CERM在环境监测应用中的有关问题归结为"泛标样"倾向和对CERM特性值误区两个方面,结合典型案例,通过不确定度评定分析相关误区或偏颇,并提出选择性使用CERM、按规定条件使用CERM、全面了解掌握CERM特性值、合理运用CERM特性值范围和慎重评价CERM特性值范围内测定结果的差异等具体对策和建议。     

Assessment of Quality for Middle Level and High School Student‐Generated Water Quality Data

Student scientists have analyzed groundwater used for drinking water in rural areas to understand groundwater quality. This was part of a greater effort to understand risks to drinking water. The data produced by middle level and high school students have not been accepted by experts because of concerns about method and student accuracy. We assessed the inherent errors associated with method accuracy, student precision, and sample variability to establish bounds for attainable trueness in water analyses. Analytical test kits and probes were evaluated for the determination of pH, conductivity, chloride, hardness, iron, total soluble metals, and nitrate. In terms of precision, all methods met or exceeded design specifications. Method trueness was variable and in general ranged from good to poor depending on method. A gage reproducibility and repeatability analysis of instrumental methods (pH and conductivity) partitioned the variances into student error (12‐46%), instrumental error (8‐21%), and random error (45‐68%). Overall, student‐generated data met some of the quality objectives consistent with the method limitations. Some methods exhibited a systematic bias and data adjustment may be necessary. Given good management of the student analyst process, it is possible to make precise and accurate measurements consistent with the methods specifications.     

Pesticides and trace elements in cannabis: Analytical and environmental challenges and opportunities

Cannabis is increasingly used for both medicinal and recreational purposes with an estimate of over 180 million users annually. Canada has recently legalized cannabis use in October 2018, joining several states in the United States of America (e.g., Colorado, California, and Oregon) and a few other countries. A variety of cannabis products including dry flowers, edibles, and oil products are widely consumed. With high demand for cannabis products worldwide, the quality of cannabis and its related products has become a major concern for consumer safety. Various guidelines have been set by different countries to ensure the quality, safety, and efficacy of cannabis products. In general, these guidelines require control of contaminants including pesticides, toxic elements, mycotoxins, and pathogens, as well as residual solvents in regard to cannabis oil. Accordingly, appropriate analytical methods are required to determine these contaminants in cannabis products for quality control. In this review, we focus on the current analytical challenges and method development for detection of pesticides and toxic elements in cannabis to meet various guidelines.     

饮用水石油类项目监测质量保证的全过程措施

介绍饮用水石油类项目监测全过程达到“空白值<0.05mg/L“的质控方法。从实验中寻找达到上述要求的定量指标———“全景空白”,从而使该项目的测量误差最小化。