环境监测实验室的量值溯源

在从事环境监测质量管理以及环境监测站实验室认可和计量认证评审工作中,发现有不少环境监测站的量值溯源只停留在对仪器设备检定的认识上,而对量值溯源概念、体系、途径和方法不甚明了,特别是对校准和检定的关系理解不清,造成一些监测项目、领域的量值统一得不到保证;检定费用又增加,不堪重负。今对环境监测实验室的量值溯源予以阐述。1　量值溯源的相关概念和释义1 1　量值一般由一个数乘以测量单位所表示的特定量的大小。1 2　测量以确定量值为目的的一组操作。1 3　溯源性通过一条具有规定不确定度的不间断的比较链,使测量结果或计…     

生态环境第三方检测机构计量器具量值溯源管理问题探讨

构建科学、准确、有效的量值溯源体系是实验室质量管理的重要内容。在国家市场监督管理总局新发布的《实施强制管理的计量器具目录》中,涉及环境监测用途的类别大幅度减少。在此背景下,研究介绍了量值溯源中检定和校准的差异及适用范围,强调不应将检测作为量值溯源的方式。分类比较了国内现有具备量传能力的计量技术机构,对目前生态环境监测领域量值溯源技术方法与实际使用需求脱节、计量服务供给侧响应不及时的短板进行了总结。建议各专业计量技术委员会加快制修订相关计量技术法规,各计量技术机构及时更新和建立相关计量标准,从而更好地满足环境检测机构对计量器具量值管理的需求。     

环境监测分析中不确定度的估算

阐述了环境监测分析中不确定度的基本概念和测定不确定度的评估过程，介绍了A类不确定度估算中的贝塞尔法、组合实验标准法、极差法、最小二乘法以及B类不确定度的一般信息来源及估算，并结合环境监测分析的具体情况，举例分析操作过程中不确定度各分量的估算，建立了测量结果的溯源性，对实验室提供数据的质量保证具有十分重要的意义．     

浅谈强化环境监测质量管理体系建设

针对新的历史条件下环境监测质量管理体系建设不断完善的实际需求,提出了完善监测技术体系、补充建立量值溯源基准体系、建立监测质量控制指标体系、提高环境监测人员技术能力和水平、有效运行环境监测质量体系、建立健全监测质量监督机制等6项提升环境监测质量管理水平的体系建设思路。     

环境监测机构的认可管理

我国的环境监测机构近20a来得到了很大的发展,全国现有各类环境监测机构4000余家,从业人员达7万余人。环境监测机构在各级行政部门的领导下,按照国家相关法律、法规和国家、行业的相关标准,行使环境保护技术性监测和执法性监督职能。随着我国社会主义市场经济体制的建立和加入WTO,建立、健全统一、规范的环境监测机构认可制度,不仅是与国际接轨的需要,也是环境监测机构提高自身技术能力和管理水平,参与国内、国际市场竞争的需要。1985年,《中华人民共和国计量法》颁布,其中第22条规定:“为社会提供公证数据的产品质量检验机构,必须经…     

对环境监测站通过计量认证/审查认可(验收)的实践与思考

通过克拉玛依市环境科研监测中心站计量认证／审查认可(验收)所取得的经验，指出建立符合计量认证／审查认可(验收)评审准则的质量体系，按程序文件实施环境监测全程序质量控制，在日常工作中做好样品管理、仪器设备(标准物质)管理、量值溯源、记录和报告的管理等基础工作是计量认证／审查认可(验收)工作取得成功的保证；全员参与是计量认证／审查认可(验收)工作取得成功的前提；加强人员培训，切实掌握计量认证／审查认可(验收)评审准则的要求是计量认证／审查认可(验收)工作顺利进行的基本条件。     

采用能力验证数据评估环境监测结果测量不确定度

测量不确定度评估是实验室检测能力的体现,能力验证是实验室质量控制的有效方法,对环境监测领域实验室采用能力验证数据进行测量结果不确定度评估方法进行了研究。依据Nordtest准则,根据实验室内再现性标准差和测量偏倚,评估了重铬酸钾法测定水中质量浓度为100 mg/L的化学需氧量测量结果的相对不确定度为6.00%。该评估方法避免了ISO GUM评定方法自下而上不确定度评估过程的繁琐,还充分考虑了实验室内外误差的来源,能够促进环境监测结果不确定度评定的一致性。     

深圳市环境监测站实验室认可的实践与思考

介绍了深圳市环境保护监测站实验室认可工作的具体做法。指出建立完善的质量体系 ,规范样品管理 ,实施文件控制 ,严格环境监测设备 (标准物质 )管理 ,保证量值溯源准确 ,全面规范环境监测记录和环境监测报告等 ,是实施实验室认可的重要工作 ;领导重视 ,专人负责 ,全员参与是实验室认可工作取得成功的前提 ,加强人员培训 ,切实掌握ISO/IEC导则 2 5的要求是开展实验室认可工作的基础条件     

浅谈环境监测仪器的量值溯源

介绍了环境监测仪器量值溯源的基本知识,阐述了检定与校准的区别,归纳总结了环境监测仪器量值溯源的途径与方法.旨在提高环境监测质量管理人员及监测人员对仪器检定和校准工作重要性的认识,以便更准确、更规范地开展工作.     

关于环境监测社会化的调查与思考

环境监测社会化在我国还处于探索阶段,社会化的根本目的是有序引入社会力量共同参与,提供更多、更好的监测服务。为此,环境监测社会化应坚持政府主导、社会参与的总体格局,引导环保监测机构重点强化环境监测网络运行管理、技术标准研发制定、监督性或执法性监测、环境质量预报预警及污染事故应急监测、监测数据质量控制及汇总分析等职能,同时因地制宜地确定环境监测社会化区域策略,严格规范社会检测的行为,确保监测市场有序开放、公平竞争、风险可控。     

Measurement instability and temporal bias in chemical soil monitoring: sources and control measures

Concern that human impacts on the environment may be harmful to natural resources such as soils as well as to living conditions is the major motivation for long-term environmental monitoring. However, the evidence that measurement bias is not constant through time affects time series as an artifact; this also holds true for chemical soil monitoring. Measurement instabilities occur along the whole measurement chain, from soil sampling to the expression of results. The first step in controlling measurement instability is to identify its relevant sources, and the second is to control it by stabilizing, minimizing, or quantifying measurement instability. For all five steps in the measurement process, from soil sampling to the expression of the analytical results, sources of measurement instability are identified and measures of control discussed, leading to the main conclusion concerning the requirement to continuously control the relevant environmental and measurement boundary conditions that may affect measurement instability. The innovative aspect of this paper consists in explicitly addressing measurement instability in chemical soil monitoring and tracking it along the whole measurement chain. The paper is also a plea for a change of paradigm in long-term environmental monitoring, namely to consider temporal measurements as unstable unless their degree of stability is traceably demonstrated, adequately quantified, and included in interpretation.     

环境空气VOCs在线监测中标准气体的比对研究

环境空气中挥发性有机物(VOCs)的在线监测技术近年来受到普遍关注。相对于传统的离线手工监测,在线监测能够解决监测数据时空代表性不足的问题,同时更好地满足环境质量连续监测和研究的需要。现有环境空气常规气体在线监测技术规范对量值溯源有较高的要求,其中标准气体的溯源和比对是质量控制和质量保证的根本。通过构建上海市环境空气VOCs在线监测的标准气体实验室比对测试流程,提出了标准气体比对结果的评价指标及方法,以确保在线监测数据的准确性和可比性。结果显示,6瓶臭氧前体混合物标准气体中,90%以上物种的测定结果的相对偏差在±10%以内,个别物种超出范围,说明定期开展标准气体比对对于VOCs在线监测的质控和质保具有重要意义。     

由石油类应急监测现状探寻水中石油类监测的突破

突发环境事件发生后,对污染物质、污染物浓度、污染范围及其动态变化情况进行监测是环境应急监测的基本工作要求。在不能利用管理手段有效获取污染来源等信息的情况下,开展溯源应急监测成为突发环境事件处理处置的重要需求。然而通过资料调研及应急监测案例分析发现,石油类水体突发环境事件应急监测大多存在采样代表性不够、溯源手段不健全、特征污染物监测不全面,以及现行石油类监测方法不能完整说清污染状况等问题或不足。因此,建议通过优化整合水中石油类指标监测标准,构建与石油类污染特征相适应的技术规范及配套监测分析方法,以达到精准、全面反映石油类水体污染状况的目的。     

SI-traceable certification of Cu, Cr, Cd and Pb in sediment and fly ash candidate reference materials

Many fields in environmental analytical chemistry deal with very low limits and thresholds as set by governmental legislations or transnational regulations. The need for the accuracy, comparability and traceability of analytical measurements in environmental analytical chemistry has significantly increased and total uncertainties are even asked for by accreditation bodies of environmental laboratories. This paper addresses achieving these goals to guarantee accuracy, quality control, quality assurance or validation of a method by means of certified reference materials. The assessment of analytical results in certified reference materials must be as accurate as possible and every single step has to be fully evaluated. This paper presents the SI-traceable certification of Cu, Cr, Cd and Pb contents in geological and environmentally relevant matrices (three sediments and one fly ash sample). Certification was achieved using isotope dilution (ID) ICPMS as a primary method of measurement. In order to reduce significantly the number of analytical steps and intermediate samples a multiple spiking approach was developed. The full methodology is documented and total uncertainty budgets are calculated for all certified values. A non-element specific sample digestion process was optimised. All wet chemical digestion methods examined resulted in a more or less pronounced amount of precipitate. It is demonstrated that these precipitates originate mainly from secondary formation of fluorides (essentially CaF2) and that their formation takes place after isotopic equilibration. The contribution to the total uncertainty of the final values resulting from the formation of such precipitates was in general < 0.1% for all investigated elements. Other sources of uncertainty scrutinised included the moisture content determination, procedural blank determination, cross-contamination from the different spike materials, correction for spectral interferences, instrumental background and deadtime effects, as well as the use of either certified values or IUPAC data in the IDMS equation. The average elemental content in the sediment samples was 30-130 micrograms g-1 for Pb, 0.5-3 micrograms g-1 for Cd and 50-70 micrograms g-1 for Cu. Cr was measured in one sample and was about 60 micrograms g-1. The concentrations in the fly ash sample were up to 2 orders of magnitude higher. Expanded uncertainty for the investigated elements was about 3% (coverae factor k = 2) except for Cr, (measured by high resolution ICPMS), for which the expanded uncertainty was about 7% (k = 2).     

An argument for ecosystem level monitoring

One objective of environmental monitoring programs is documentation of qualitative and quantitative environmental changes in response to external stresses, including chemical contamination. Chemical contaminant, biological, and ecological measurements have been used as environmental monitors. Contaminant monitoring allows estimation of exposures; biological and ecological monitoring allow estimation of uptake and effects.Measurements of ecosystem homeostasis such as nutrient cycling processes have been shown to be good ecosystem level monitors. The rate of dissolved nutrient loss from ecosystems has been conclusively shown to increase as a function of chemical contamination until a new equilibrium is reached, the pollutant input has become negligible, or until nutrient pools have been depleted. Consequently, nutrient pools in environmental strata and in biota are altered and eventually depleted by chemical stress.The use of nutrient cycling to determine sensitive responses to and long-term changes for chemical contamination is an essential monitoring strategy for environmental management and compliance purposes. Measurements of export (rapid response) and pools (long-term consequences) are within current technology, are cost-effective, and allow rapid implementation of remedial measures or environmental controls.Paper presented at a Symposium held on 20–21 April 1982, in Edmonton, Alberta, Canada.     

化工园区环境监控预警系统构建探讨

指出化工园区环境监控预警系统的建设是提升化工园区环境管理能力和预警水平的要求。明确了化工园区环境监控预警体系的建设目标。从环境风险评估、环境监控网络的构建、环境监控预警能力建设、环境监控预警平台建设、质量控制体系及应急体系建设等方面系统阐述了化工园区环境监控预警系统的构建内容,为化工园区环境监控预警系统的建设提供参考。     

Collaborative study to improve the quality control of rare earth element determinations in environmental matrices

In order to control the quality of rare earth determinations in environmental matrices, the Standards, Measurements and Testing Programme (formerly Community Bureau of Reference, BCR) of the European Commission has started a project, the final aim of which is to certify four types of matrices (tuna muscle, mussel tissue, aquatic plant and estuarine sediment) for their contents of a range of rare earth elements (Sc, Y and the lanthanides: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu). The elements U and Th were added to the study. The first part of this project consisted of an interlaboratory study which aimed to test the feasibility of preparation of environmental reference materials and to detect and remove most of the pitfalls observed in rare earth determinations. This paper presents the preparation of the four matrices for the intercomparison study and for the candidate reference material. The main results are presented of the interlaboratory study that was carried out prior to the certification campaign. This collaborative trial is the first attempt ever carried out at this scale to evaluate the state-of-the-art of rare earth determinations in the environment. Its impact on the improvement of chemical measurements will have positive effects on the comparability of data necessary for environmental monitoring.     

浅析被动式FTIR走航监测技术在废气监测中的应用

与传统的监测技术相比,走航监测技术具有监测范围大、响应快速、机动性强的特点,在工业园区及企业废气排放的监测监控、溯源定位方面应用较为广泛。被动式傅里叶红外(FTIR)走航监测技术可以动态、立体、实时地扫描周围一定空域气体中的污染物质。采用被动式FTIR走航监测车,对不同的工业园区企业进行监测,结果表明,被动式FTIR走航监测可对实时发现的超标或异常有毒有害、易燃易爆、异味因子排放装置进行及时的定位和溯源,为环保部门和企业对污染物进行进一步精细化管控提供了有力的科学依据。