Internal and external quality control in the toxicological analysis of blood and urine samples in the Federal Republic of Germany

Summary Due to a technical rule for dangerous agents (TRGS 410), issued by the Ministry of Labor in the Federal Republic of Germany in 1979, toxicological analyses in biological materials must be carried out under conditions of statistical quality control. This quality-control scheme provides internal and external control programmes. For internal quality control, the results of many years of experience with five commercially available control specimens and one home-made control have been evaluated. The control samples showed good, comparable results over a long period. Except in a few cases, there was good agreement between our results and the assigned values. Since 1982, the German Society of Occupational Medicine has offered eight intercomparison programmes for external quality. In samples from 80–90 laboratories, 6 metals in blood and around 20 inorganic and organic parameters in urine in 2 concentration adjustments have been analysed. Successful participation was certified if both results obtained for one parameter were within the tolerance range (assigned] value ± 3 SD). The average success rate was around 60%.     

Comparison of 90Y and 177Lu measurement capability in UK and European hospitals

Comparison exercises involving ⁹⁰Y and ¹⁷⁷Lu were performed during 2009 and 2012, respectively, to assess the measurement capability of hospitals in the UK and Europe. The results from the measurement of a typical liquid solution of ⁹⁰Y show that only 40% of participants could measure the solution to within 5% of the certificated value and that a significant −6% bias was present due to the use of non-standard geometries for the calibration of equipment. The results from the measurement of a standard liquid solution of ¹⁷⁷Lu show that 81% of participants could measure to within 5% of the certificated value and in fact 65% of these results were within 2% of the certificated value, showing administered activities can be far more accurately measured for ¹⁷⁷Lu than for ⁹⁰Y and that ¹⁷⁷Lu has a far smaller geometry dependence. These studies were performed to identify specific measurement issues in the user community and to identify areas where future research should be focused. In addition to this the work allows the participants to adjust measurement practice and identify key measurement issues.     

中日γ能谱分析土壤样品中放射性核素的比对

目的 通过开展γ能谱测量分析比对活动,检验比对样品的采集、制备、测量和分析全过程,以促进放射性核素γ能谱测量分析技术的发展。方法 由中国疾病预防控制中心辐射防护与核安全医学所采集和制备环境土壤样品,比对各方分别对两个土壤样品中的²¹⁴Pb、²¹⁴Bi、²⁰⁸Tl、²²⁸Ac、⁴⁰K和¹³⁷Cs 6个核素进行测量和分析。根据3个实验室约定测量结果的评定标准,利用各实验室上报的活度浓度和总不确定度数据计算测量结果评价变量(En)值。结果 每两个实验室间计算的En值均小于1,3个实验室的结果均为可接受的结果。结论 各比对方的测量结果在一定范围内是一致的。本次比对既检验了比对方实验室的核素分析水平,又促进了本实验室样品制备中均匀性检验能力的提高。     

Low-dose-rate iodine-125 seed air kerma strength measurement intercomparison

PurposeThe purpose of this study was to investigate the rate of compliance of air kerma strength (AKS) measurements of iodine-125 (I-125) seeds with international recommendations by departments in Australia and determine the potential impact of noncompliance.Methods and MaterialsTo achieve this aim, we present an intercomparison of AKS measurements for a single I-125 seed performed by 11 radiotherapy departments in Australia. Measurements were performed at two sites, with each participating department traveling to one of the two host sites and measuring the AKS using their own equipment and local protocols. Each of the AKS measurements was compared with each other and the manufacturer-certified AKS.ResultsNine of the 11 participating departments measured AKS fell within ±3% of the manufacturer's calibration certificate value, whereas all participating departments measured AKS within ±5% of the manufacturer's calibration certificate value. The total spread of the measured AKS among the 11 departments was 7.7%. Only two of the 11 participating departments complied with international recommendations and had their well chamber calibrated within the last 2 years. In addition, 2 of the 11 departments used a well chamber calibrated that was calibrated with a different seed model used during the intercomparison, whereas 4 of the 11 departments calibrated their well chamber “in-house” using a factory-calibrated seed provided by the seed manufacturer.ConclusionsA significant variation in the methods used and frequency of calibration of well chambers were observed among the participating departments. The results of this study support the international recommendations on frequency and methodology of well chamber calibration. Failure to follow these recommendations significantly increases the uncertainty in AKS measurement of I-125 seeds.     

222Rn-220Rn分辨探测器参加国际比对结果分析

目的 提高²²²Rn与²²⁰Rn的累积测量水平,保证测量结果的准确性与可靠性。方法 采用中国疾病预防控制中心辐射防护与核安全医学所的氡课题组（以下简称本实验室）改进的LD-P型²²²Rn-²²⁰Rn分辨探测器参加日本放射线医学综合研究所（NIRS）组织的²²²Rn-²²⁰Rn累积探测器国际比对。将²²²Rn-²²⁰Rn分辨探测器寄往日本,在NIRS的²²²Rn室和²²⁰Rn室进行不同条件下的比对,暴露结束后再寄回本实验室进行蚀刻与分析,测量结果告知NIRS。最后NIRS将²²²Rn与²²⁰Rn暴露参考值回馈本实验室。结果 在高²²²Rn和低²²²Rn条件下,测量值与NIRS提供的参考值的相对百分偏差（RPD）分别为-12.0%、-11.8%;变异系数（COV）分别为3.0%、6.2%。在高²²⁰Rn和低²²⁰Rn条件下,测量值与NIRS提供的参考值的相对百分偏差（RPD）分别为-0.8%、-8.0%;变异系数（COV）分别为6.7%、4.5%。结论 本次比对LD-P型探测器²²²Rn与²²⁰Rn的测量结果均为NIRS规定的Ι级结果（PRD<10%）,比对结果较好。     

2014年参加全国γ能谱分析质量控制比对结果

目的 总结2014年放射性核素γ能谱分析质量控制比对,验证放射性核素分析方法的可靠性。方法 采用国家标准,利用γ能谱仪分析土壤比对样品中²⁰⁸Tl、¹³⁷Cs、²²⁸Ac和⁴⁰K放射性核素的含量。结果 我所实验室比对样品的测量值相对校准值偏差均< 10%,各核素比对结果无论是准确度还是精确度均满足比对要求,判定结果为"合格"。结论 比对结果证明,我所γ能谱测量系统的质量保证体系和质量控制技术是完善和有效的,放射性核素的测量分析方法、数据的处理方法也是可靠的。     

IAEASSDL放疗剂量水平电离室校准因子的国际比对

目的参加国际原子能机构(IAEA)组织的二级标准剂量学实验室(SSDL)比对,引入水吸收剂量校准因子,检查SSDL60Co放疗剂量标准的准确度,保证校准程序的可靠性和一致性.方法本SSDL给出电离室的60Co γ射线比释动能校准因子和水吸收剂量校准因子,然后将该电离室及其校准结果寄往IAEA剂量学实验室,对其进行评价,给出比对的偏差.结果比释动能校准因子比对的偏差为-0.5%,水吸收剂量校准因子的比对偏差为0.4%.结论按照IAEA要求,该项比对的最大允许偏差为±1.5%,所以这次比对结果是合格的.     

2015—2019年全国外照射个人剂量监测能力考核结果分析与总结

目的:规范个人剂量监测技术服务机构的个人剂量监测工作,提高监测能力和水平。方法:汇总2015—2019年全国外照射个人剂量监测能力考核的结果,并对考核中出现的问题进行总结与分析。结果:截至2019年,来自全国30个省、自治区或直辖市的个人剂量监测技术服务机构参加了全国外照射个人剂量监测能力考核,涉及的机构有疾控中心、职...     

2017年全国外照射个人剂量监测能力考核不确定度评定分析

目的 规范全国放射卫生技术服务机构的外照射个人剂量监测不确定度评定工作,提高不确定度评定能力和水平,确保评定质量。方法 开展2017年全国外照射个人剂量能力考核工作,对其考核报告中不确定度评定存在的问题进行分析总结。结果 提交完整考核报告及检定/校准证书机构259家,A类不确定度评定正确率为20.8%,校准、能量响应、角度响应、非线性响应B类不确定度评定正确率分别为55.2%、50.6%、25.5%、51.4%。被测量估计值及其不确定度有效位数表述正确率为34.0%。结论 关于不确定度评定方面检测机构的能力还有待提高,建议加大对检测机构不确定度评定的系统化培训力度,规范考核报告表述,从而提高测量结果报告的水平。     

Measurement of the French national tritiated-water standard by helium-3 mass spectrometry

The ³He ingrowth technique is based on the detection of the tritium radioactive daughter, ³He, by mass spectrometry. Over the last three decades it has been used extensively in oceanography and groundwater studies for measurements of very low to ultra-low levels of tritium. To compare it with the best available methods of radioactive counting, we applied this method to measure the massic activity of a tritiated-water primary standard prepared by the French Laboratoire National Henri Becquerel (LNHB). One liter of a low-level tritium solution was prepared from a small aliquot of the LNHB standard by two-step gravimetric dilution with tritium-free groundwater. Sixteen samples of this solution were analyzed at the LSCE-Saclay noble gas facility, using the ³He ingrowth method. The massic activity of the prepared solution was also measured by Liquid Scintillation Counting using the Quantulus LNHB counter and an internal calibration method with the LNHB tritiated water standard. All results agree within their standard uncertainty.