农药残留分析质量控制程序

八、分析方法和分析操作 方法确认 56 实验室内部应进行方法确认以验证方法的适用性.方法确认既是认可体系的要求,同时必须被操作过程的确认(不断发展的分析质量控制)所支持和扩展.方法中采用的所有程序步骤在可能的情况下都应被确认.如果一个方法欲被认可,在任何确认数据产生之前应向认可机构进行咨询.不同的认可机构对方法确认可能会有不同的准则.     

光电直读光谱法测定铝及铝合金中硅含量时的方法验证北大核心CSCD

基于原子发射光谱技术的光电直读光谱法主要用于金属材料的理化分析,具有制样简单、操作简便、分析快速、准确度高、可多元素同时检测等优点,在金属行业中应用广泛。实验室在开展检测工作前,必须对使用的标准方法进行方法验证,对于非标准方法、实验室制定的方法、超出预定测量范围使用的标准方法或其他扩充和修改过的标准方法进行全面的方法确认。方法验证不仅要识别标准方法的规定要求,还要通过试验证明测定结果的准确度和可靠性,这是对实验室检测能力的重要评价。     

波兰农产品中农药残留检测技术现状

介绍波兰农产品中农药残留检测技术。波兰的农药残留检测技术标准以欧盟标准为框架,在实际检测过程中各实验室可根据自身仪器设备条件、样品基质及目标农药的性质,自主开发检测方法,但需根据SANCO 12571:2013对方法进行验证,并向波兰认可中心提供验证报告。样品制备技术以基于乙腈提取/分配、Qu ECh ERS净化为主(EN 15662:2008),各实验室对标准中大部分步骤进行了调整和创新,以满足实际工作的需要;一些经改进的经典方法,如基质固相分散法(MSPD)和基于丙酮提取、二氯甲烷萃取的LUKE法在波兰农产品检测实验室也有较为广泛的应用;最终定性定量分析以GC–MS/MS和HPLC–MS/MS法为主,以GC,HPLC和紫外分光光度法等分析方法为辅。     

α-Al_2O_3比表面积标准物质的研制

选择市售α-Al2O3粉体作为比表面积标准物质候选材料,采用交叉缩分方法对标准物质样品进行分装。检验结果表明α-Al2O3标准物质样品具有良好的均匀性和稳定性(18个月)。采用国际公认的氮气物理吸附BET方法,联合测量能力经过确认的8家实验室对α-Al2O3标准物质样品进行定值,标准值比表面积为5.47 m2/g,不确定度为0.22 m2/g(k=2)。     

化学分析实验室标准工作溶液的配制及核查的探讨

CNAS-GL035:2018《检测和校准实验室标准物质/标准样品验收和期间核查指南》指出,需对标准物质进行期间核查,目的是确认其特性量值的稳定性[1].化学分析实验室在实际使用标准物质时,通常要通过混合、稀释或其他方法将标准物质配制成标准工作溶液,以其中的特性量值为其他材料赋值.标准工作溶液特性量值稳定性与准确度会直...     

有机涂层环境适应性研究进展

综述了有机涂层自然环境试验方法和实验室加速试验方法。自然环境试验方法主要有大气环境试验和海水环境试验;实验室加速试验方法不但包括模拟太阳光、热、湿热、盐雾等环境的实验室试验,还有综合模拟试验。还介绍了检测有机涂层老化的宏观分析方法、微观分析方法和电化学分析方法。其中宏观分析方法主要介绍了涂层附着力试验方法,微观分析方法则主要介绍了扫描电镜(SEM)、X射线光电子能谱仪(XPS)、傅里叶红外光谱(FTIR)及电化学交流阻抗谱法(EIS)。讨论了近年发展起来的有机涂层老化的各种机理,例如自由基降解的光老化降解机理,亲水性基团的水降解机理,热氧机理,臭氧及污染物影响的老化机理等。     

地下水检测典型挥发性有机物标准样品研究

依据我国地下水污染现状,研究制备了地下水中典型挥发性有机物(VOCs)质量控制模拟标准样品,包含4种卤代烃和6种苯系物,经过气相色谱/质谱分析检测,均匀性和稳定性良好。组织行业内9家实验室,探索开展水中挥发性有机物检测的协作定值研究。开展不确定度来源分析和量值评定,标准样品的标准值和扩展不确定度(k=2)为:三氯甲烷(60.6±5.4)μg/L、四氯化碳(60.2±7.4)μg/L、三氯乙烯(60.4±5.8)μg/L、四氯乙烯(60.6±7.6)μg/L、苯(60.9±4.2)μg/L、甲苯(60.4±4.8)μg/L、乙苯(60.7±5.0)μg/L、邻二甲苯(60.5±6.2)μg/L、间二甲苯(60.4±6.2)μg/L、对二甲苯(60.4±6.2)μg/L。本标准样品主要用于地下水、地表水和饮用水环境监测工作中质量控制、分析方法验证、仪器性能的核查以及技术人员能力考核等。     

分析方法的认证

一个方法在应用到分析实际试样之前，必须经过严格的认证，以确认分析方法在准确度、精密度、适用的浓度范围以及抗干扰能力等方面是否能够达到试样对分析方法的要求．另一方面，即使是可靠的方法，例如法定的分析方法，当一个实验室或个人初次使用时，也要通过认证，以证明在当时的条件下方法能被正确地执行．     

《分析测试统计方法和质量控制》书讯

<正>曹宏燕等编著。《分析测试统计方法和质量控制》全书分十三章,七十三万余字,介绍了分析测试及其试验研究中常用的数理统计方法,包括误差和误差的分布、统计检验、方差分析、正交设计、回归分析等统计方法的理论与实践。本书紧密结合国际标准(ISO)、国家标准(GB)及中国合格评定国家认可委员会(CNAS)等有关实验室管理规范、标准和认可要求,阐述了实验室协同试验和管理中测量结果精密度试验和应用、能力验证及其稳健统计、测量不确定度评定、标准物质研制及应用、分析方法的评价及分析结果的表     

理化实验室标准物质的管理

<正>标准物质是具有准确的特性量值、高度均匀与稳定性良好的测量标准,是量值传递的物质基础。在理化检测中,标准物质可被用于测量系统的校准、测量程序的评估、给其他物质赋值、质量控制和分析方法的评价等。这些测量都依赖于标准物质,并由标准物质将测量的结果溯源到国际单位制(SI)。因此,标准物质是实验室开展检测工作所必需的重要资源,其正确的管理和使用是实验室检测工作的一项重要基础内容,也是实验室质量管理体系的重要     

用平行双样测定结果相对偏差限值评估方法验证实验重复性限合理性的研究

分析方法标准验证实验得到的分析方法基本性能参数重复性限和再现性限是日常检测工作质控规范重要依据。以环境监测领域土壤、沉积物及固废样品中无机元素分析为例,考察了已颁布执行的标准文本和在生态环境部官网公开征求意见的分析方法标准中重复性限。将重复性限转化为相对偏差后,与日常检测工作中质控限值进行了比较。根据目前现行有效的平行双样测定结果相对偏差限值,方法验证数据有多大比例符合质控要求？根据方法验证结果,平行双样测定结果相对偏差限值有无改进可能？从上述两个角度进行了研究。研究结果表明：土壤、沉积物、固体废弃物中无机元素的测定,不同文献来源相同分析方法标准和不同分析方法标准,其重复性限转化得到的平行测定相对偏差合格率存在明显区别;用平行测定相对偏差限值可以快速判断标准文本中的重复性限是否合理,审核方法验证数据质量是否满足要求。基于已有标准文本方法验证数据,探讨了修改平行测定结果相对偏差限值可行性。     

Development and validation of gas chromatography-mass spectroscopy method for determination of prilocaine HCl in human plasma using internal standard methodology

The accurate determination of prilocaine HCl levels in plasma is important in both clinical and pharmacological/toxicological studies. Prilocaine HCl is quickly hydrolyzed to o-toluidine, causing methemoglobinemia. For this, the present work describes the methodology and validation of a GC-MS assay for determination of prilocaine HCl with lidocaine HCl as internal standard in plasma. The validation parameters of linearity, precision, accuracy, recovery, specificity, limit of detection and limit of quantification were studied. The range of quantification for the GC-MS was 20-250 ng/mL in plasma. Within-day and between-day precision, expressed as the relative standard deviation (RSD) were less than 6.0%, and accuracy (relative error) was better than 9.0% (n = 6). The analytical recovery of prilocaine HCl and IS from plasma has averaged 94.79 and 96.8%, respectively. LOQ and LOD values for plasma were found to be 20 and 10 ng/mL, respectively. The GC-MS method can be used for determination from plasma of prilocaine HCl in routine measurement as well as in pharmacokinetic studies for clinical use.     

Development of a Gas-Tight Syringe Headspace GC-FID Method for the Detection of Ethanol,and a Description of the Legal and Practical Framework for Its Analysis,in Samples of English and Welsh Motorists’ Blood and Urine

Ethanol is the most commonly used recreational drug worldwide. This study describes the development and validation of a headspace gas chromatography flame ionisation detection (HS-GC-FID) method using dual columns and detectors for simultaneous separation and quantitation. The use of a dual-column, dual-detector HS-GC-FID to quantitate ethanol is a common analytical technique in forensic toxicology; however, most analytical systems utilise pressure-balance injection rather than a simplified gas-tight syringe, as per this technique. This study is the first to develop and validate a technique that meets the specifications of the United Kingdom’s requirements for road traffic toxicology testing using a Shimadzu GC-2014 gas-tight syringe. The calibration ranged from 10 to 400 mg/100 mL, with a target minimum linearity of r2 > 0.999, using tertiary butanol as the internal standard marker. The method has an expanded uncertainty at 99.73% confidence of 3.64% at 80 mg/100 mL, which is the blood alcohol limit for drink driving in England and Wales. In addition, at 200 mg%—the limit at which a custodial sentence may be imposed on the defendant—the expanded uncertainty was 1.95%. For both the 80 mg% and 200 mg% concentrations, no bias was present in the analytical method. This method displays sufficient separation for other alcohols, such as methanol, isopropanol, acetaldehyde, and acetone. The validation of this technique complies with the recommended laboratory guidelines set out by United Kingdom and Ireland Association of Forensic Toxicologists (UKIAFT), the recently issued Laboratory 51 guidelines by the United Kingdom Accreditation Service (UKAS), and the criteria set out by the California Code of Regulations (CCR), 17 CCR § 1220.1.     

Validating automated analytical instruments to meet regulatory and quality standard requirements

Analytical laboratories are more and more faced to meet official regulatory requirements as described in FDA and EPA good laboratory practice, good automated laboratory practice and good manufacturing practice regulations or to officially establish quality systems, such as specified in the ISO 9000 Series quality standards, in the ISO Guide 25 or in the EN 45001 guidelines. The impact on analytical instrumentation will be the requirement for stringent validation of analytical equipment and methods which increase the overall analysis costs. An overview is presented on the validation requirements using e.g. gas chromatography, high performance liquid chromatography, capillary electrophoresis and UV-visible spectroscopy and on the strategy to meet such needs at minimal extra costs with the help of an instrument vendor. It is recommended to use instrument hardware that has already built-in tools for self-verification and which is to be validated at the vendor's site. Performance testing in the user's laboratory is done using standard operating procedures as supplied with the instrument. If resources in the user's laboratory are limited, the performance verification is done by the vendor. Software and the entire computer system is validated prior to shipment at the vendor's site. Acceptance testing is done in the user's environment following the vendor recommendations. Analytical methods are validated automatically at the end of method development using a dedicated software. The software can be customized such that it can also be used for daily automated system suitability testing. Security and integrity of analytical data are ensured by saving the raw data together with instrument conditions and instrument log-books in check-sum protected binary register files for long-term archiving.     

药物分析中薄层色谱的方法认证

在药物分析中,针对所要求的性能参数,对一个薄层色谱程序的各个环节必须进行的认证方法和认可标准进行了讨论。建议当提出结果报告时,应附上关于对方法的认证参数和认证方法的说明。     

Automated ion-selective measurement of lithium in serum. A practical approach to result-level verification in a two-way method validation

 The Quality Assurance Department of Medix Diacor Labservice evaluated a two-way method validation procedure for serum lithium quantification in therapeutic drug monitoring In the process of a company fusion and rationalization of two considerably large production lines, three independent ion-selective electrode (ISE) methods were surveyed, among many others. While tailoring the new medical laboratory production, subcontracting from a collaborating company was discontinued. Likewise, modernization of the ISE instrumentation was unavoidable to increase throughput and effectiveness. It was important that the new result levels should be comparable both with the former subcontractor's levels and with the levels reported from the previously existing instrumentation. The aim of this study was to evaluate the most crucial performance characteristics of a novel lithium method in comparison to the two ISE test methods being withdrawn. The standardized lithium test method was inspected in terms of linear measurement range, analytical variation, bias, past and on-going proficiency testing, in addition to method comparison, to achieve the desired analytical goals. Fulfilling the accreditation requirements in terms of the introduced method validation parameters is discussed. Received: 19 April 2000 / Accepted: 26 July 2000     

Determination of amphetamine in dog plasma by gas chromatography with mass selective detection

This paper describes the validation of an analytical method for the determination of amphetamine in beagle dog plasma by gas chromatography coupled to mass spectrometry (GC-MS). d-Amphetamine-d(6) was used as the internal standard. The method consisted of a rapid single-step liquid-liquid extraction and derivatization of amphetamine with 2,2,2-trichloroethyl chloroformate, followed by sensitive GC-MS detection. This is the first report utilizing the combination of trichloroethyl chloroformate as a derivatization reagent and a deuterated amphetamine analog as an IS for the quantification of amphetamine in plasma. The method was validated in terms of specificity, curve fit, precision, accuracy, recovery and stability, and was acceptable according to FDA draft guidelines for validation of bioanalytical methods. The limit of detection was 0.65 ng/mL. The calibration range was 5-150 ng/mL. The validated method was successfully employed for the quantitation of amphetamine in dog plasma samples for pharmacokinetic profiling.     

化学标准物质期间核查方法

从认可实验室管理的角度,阐述了化学标准物质期间核查的目的和意义。化学标准物质常见期间核查方法有实验室比对或能力验证、标准物质间比对、控制图法、允差法及标定法。结合实例介绍了化学标准物质期间核查的具体过程,为开展化学标准物质期间核查工作提供参考。