Development of a reference material for residues of chlorfluazuron and fluazuron in beef fat ACSL CRM 3

A beef fat sample was prepared and tested as candidate reference material for the pesticides chlorfluazuron (CFZ) and fluazuron (FZN). An analytical method employing HPLC with UV absorbance detection was developed for homogeneity and stability testing. The material consisted of beef fat spiked with acetone solutions of CFZ and FZN to achieve concentrations close to 1.0 mg/kg for each compound. The coefficients of variation of 7 analyses carried out to test between-jar homogeneity were 1.8% and 2.3% for FZN and CFZ, respectively. No instability of CFZ was detected over a three month period. The candidate reference material was found to be suitable for certification by interlaboratory testing.     

Development and certification of reference materials for residues of organochlorine and organophosphorus pesticides in beef fat ACSL CRM 1 and 2

Beef fat samples were prepared and tested as candidate reference materials for organochlorine and organophosphorus pesticides. The CRMs consisted of beef fat spiked with pesticide solutions. One sample (ACSL CRM 1) was prepared containing close to 0.2 mg/kg of each of the organochlorine pesticides dieldrin and heptachlor epoxide. A second sample (ACSL CRM 2) was prepared containing close to 0.8 mg/kg of each of the organophosphorus pesticides diazinon, chlorpyrifos and ethion. The spiking levels and homogeneity of the materials were verified. The coefficients of variation of 5 analyses carried out to test between-jar homogeneity for each reference material were dieldrin, 3.5%; heptachlor epoxide, 1.1%; diazinon, 2.1%; chlorpyrifos, 1.2% and ethion, 3.1%. No instability in any of these compounds was detected over a twelve month period. The candidate reference materials were found to be suitable for certification by interlaboratory testing. The certification process was based on a two-stage nested design described in ISO Guide 35. Analysis of results reported by collaborating laboratories provided an assessment of the homogeneity of the reference materials. The certified values together with their upper and lower 95% confidence limits are: ACSL CRM 1*Dieldrin*0.199 mg/kg **(0.188, **0.210 mg/kg) *Heptachlor epoxide*0.194 mg/kg **(0.176, **0.212 mg/kg) ACSL CRM 2*Diazinon*0.805 mg/kg **(0.755, **0.855 mg/kg) *Chlorpyrifos*0.790 mg/kg **(0.728, **0.852 mg/kg) *Ethion*0.813 mg/kg **(0.746, **0.879 mg/kg). A certificate for each material was prepared according to the guidelines set out in ISO Guide 31. Received: 25 April 1997 / Revised: 19 August 1997 / Accepted: 28 August 1997     

Development and certification of reference materials for residues of organochlorine and organophosphorus pesticides in beef fat ACSL CRM 1 and 2

Beef fat samples were prepared and tested as candidate reference materials for organochlorine and organophosphorus pesticides. The CRMs consisted of beef fat spiked with pesticide solutions. One sample (ACSL CRM 1) was prepared containing close to 0.2 mg/kg of each of the organochlorine pesticides dieldrin and heptachlor epoxide. A second sample (ACSL CRM 2) was prepared containing close to 0.8 mg/kg of each of the organophosphorus pesticides diazinon, chlorpyrifos and ethion. The spiking levels and homogeneity of the materials were verified. The coefficients of variation of 5 analyses carried out to test between-jar homogeneity for each reference material were dieldrin, 3.5%; heptachlor epoxide, 1.1%; diazinon, 2.1%; chlorpyrifos, 1.2% and ethion, 3.1%. No instability in any of these compounds was detected over a twelve month period. The candidate reference materials were found to be suitable for certification by interlaboratory testing. The certification process was based on a two-stage nested design described in ISO Guide 35. Analysis of results reported by collaborating laboratories provided an assessment of the homogeneity of the reference materials. The certified values together with their upper and lower 95% confidence limits are: ACSL CRM 1*Dieldrin*0.199 mg/kg **(0.188, **0.210 mg/kg) *Heptachlor epoxide*0.194 mg/kg **(0.176, **0.212 mg/kg) ACSL CRM 2*Diazinon*0.805 mg/kg **(0.755, **0.855 mg/kg) *Chlorpyrifos*0.790 mg/kg **(0.728, **0.852 mg/kg) *Ethion*0.813 mg/kg **(0.746, **0.879 mg/kg). A certificate for each material was prepared according to the guidelines set out in ISO Guide 31.     

高效液相色谱法测定食品中氟啶脲的残留量

建立了高效液相色谱测定食品中氟啶脲残留量的方法.样品中的氟啶脲经正己烷或乙腈提取,弗罗里硅土净化后,以乙腈-水( 85:15,v/v)混合溶液为流动相,经C18色谱柱分离,紫外检测器(260 nm)测定.结果表明:氟啶脲在0 05 ～2.0 mg/L范围内线性良好(相关系数为0 999 8),定量限(以信噪比为10计)...     

Development of a certified reference material for cachaça: an effective material for quality assurance

Cachaça is the typical and genuine denomination for the sugar cane beverage produced in Brazil. It has an alcoholic content between 38 and 48 % by volume, at 20 °C, and is obtained from the distillation of fermented sugar cane juice with the possible addition of up to 6 g/L of sugar, expressed by sucrose. This paper aims to outline the approach taken for the certification of the mass fraction of individual alcohols and their associated uncertainties in a cachaça certified reference material (CRM) produced by the Organic Analysis Laboratory of the Chemical Metrology Division of Inmetro. The requirements of ISO Guide 31, ISO Guide 34 and ISO Guide 35 were followed for the certification. This included the assessment of the degree of homogeneity of the material, the short-term stability study to determine the transport conditions, the long-term stability study to establish the shelf life and storage conditions of the CRM and the characterization process. The certified values were determined by two analytical techniques: gas chromatography coupled to mass spectrometry and gas chromatography with flame ionization detection. In order to support the routine testing of cachaça, in helping analytical laboratories validate and standardize their methods, the certified reference material (CRM 02.1/10.003b) was developed and certified for the mass fractions of methanol (9.18 mg/100 g ± 0.82 mg/100 g), 2-butanol (4.15 mg/100 g ± 0.40 mg/100 g), 1-butanol (1.30 mg/100 g ± 0.18 mg/100 g), isobutanol (24.0 mg/100 g ± 1.0 mg/100 g) and 1-propanol (29.4 mg/100 g ± 1.3 mg/100 g) in a spiked cachaça.     

气相色谱法测定土壤中乙虫腈的不确定度评定

根据《化学分析中不确定度的评估指南》提供的不确定度分析思路,对气相色谱法测定土壤中乙虫腈的不确定度进行了评估,分析了影响测量不确定度的各个因素。对实际土壤样品中的乙虫腈残留量进行了测定,得到乙虫腈农药残留量为(1.75±0.15)mg/kg,置信概率为95%,k=2。     

Development of clenbuterol reference materials: lyophilized bovine eye samples free of clenbuterol (CRM 673) and containing clenbuterol (CRM 674)

The certification by inter-laboratory testing of two candidate reference materials (RMs) for the mass concentration of the anabolic agent clenbuterol in bovine eye material is described: RM 674 with ca 10 microg clenbuterol per kg of eye matrix and RM 673 clenbuterol-free eye matrix as the negative control (<0.50 microg kg(-1)). Both candidate RMs were certified by eleven EU laboratories, and sixty-six accepted replicate measurements were included in the "Certification Study". The precision of the measurement process was assessed by calculation of the standard variation determined within each laboratory during the certification step. The study was performed according to the "Guidelines for the production and certification of BCR reference materials" and to "ISO guide 31, 33, and 35". The certified clenbuterol mass concentration for clenbuterol-free eye material CRM 673 (calculated on the basis of clenbuterol as the free base) was <0.50 microg kg(-1). The corresponding concentration for clenbuterol-containing eye material CRM 674 was 9.42 +/- 0.88 microg kg(-1). These certified values are very close to the desired target concentration of <0.5 microg kg(-1) and ca 10 microg kg(-1). This study has demonstrated that successful certification of clenbuterol-containing and clenbuterol-free bovine eye materials is possible.     

Certification of the mass fractions of trace elements and pentachlorophenol in an impregnated wood reference material

The resource-saving utilisation of recovered waste wood is a matter of growing concern. In several European countries, this utilisation is governed by regulations and is dependent on the contents of certain trace elements and organic compounds. Thus, for decision-making with respect to waste wood management (recycling or combustion), reliable analytical data are needed and, due to their great economic and environmental impact, must be assured by appropriate quality control. To support the improvement in quality assurance in waste wood analysis, for the first time, a wood reference material was certified for its mass fractions of arsenic, cadmium, chromium, copper, lead, mercury, and pentachlorophenol (PCP). These analytes were selected because they represent typical constituents of wood preservatives most widely used in the past. Material preparation and testing of homogeneity and stability were carried out by BAM Federal Institute for Materials Research and Testing. The certification measurements were performed involving selected laboratories with documented expertise in the field of waste wood analysis. The certified values and their corresponding uncertainties were assigned in full compliance with the requirements of ISO Guide 35. The certified mass fractions and their expanded uncertainties (k = 2) are as follows: (3.1 ± 0.5) mg/kg for As, (3.02 ± 0.24) mg/kg for Cd, (36.4 ± 2.6) mg/kg for Cr, (22.9 ± 1.7) mg/kg for Cu, (0.60 ± 0.14) mg/kg for Hg, (39 ± 4) mg/kg for Pb, and (7.9 ± 0.6) mg/kg for PCP. The certified material is available as European Reference Material ERM^®-CD100.     

含铅黄铜儿童仿真饰品标准物质的研制

4介绍含铅黄铜儿童仿真饰品标准物质的研制方法。以铜锭、锌锭、铅粒为原料,利用坩埚熔炼及模具加工制备黄铜儿童仿真饰品标准物质,采用电感耦合等离子体发射光谱法进行均匀性检验、稳定性检验和定值。从样品中随机抽取15份进行均匀性检验,经F检验表明在95%的置信区间内样品均匀性良好。在常温条件下,经过12个月长期稳定性试验考察,结果表明样品稳定性良好。铅含量定值结果为136.1 mg/kg,合成扩展不确定度为0.72 mg/kg(k=2)。该标准物质满足ISO Guide 35:2006技术要求,可用于黄铜儿童仿真饰品检测的方法校正和质量控制。     

Establishment of SI-traceable reference values for the content of various elements in the IMEP-14 sediment sample

For the first time in the International Measurement Evaluation Programme (IMEP)-14, a sediment sample was offered to analytical laboratories to perform measurements of As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, U and Zn. In line with IMEP policy, the results were presented according to the certified / assigned reference values established by several reference laboratories around the world. The certification campaign is described in detail. Isotope dilution mass spectrometry was applied as a primary method of measurement, whenever possible, to achieve SI-traceable results. For reference measurements of As, Fe, Hg and Zn, k₀-neutron activation analysis and Zeeman atomic absorption spectrometry were applied. The reference values (ranges) were characterised as ”certified” (for Cd, Cr, Pb, Ni and U) or ”assigned” (for As, Cu, Fe, Hg and Zn) according to IMEP policy. The measurement uncertainty of the certified / assured reference values was calculated according to the ISO/BIPM Guide. Received: 7 June 2001-10-27 Accepted: 19 August 2001     

Producing SI-traceable reference values for Cd, Cr and Pb amount contents in polyethylene samples from the Polymer Elemental Reference Material (PERM) project using isotope dilution mass spectrometry

 The present paper describes the certification of the amount content of Cd, Cr and Pb in two different polyethylene materials within the third phase of the Polyethylene Elemental Reference Material (PERM) project. The analytical procedure to establish the reference values for Cd, Cr and Pb amount contents in these materials is based on isotope dilution mass spectrometry used as a primary method of measurement. Cd and Pb were measured with inductively coupled plasma-mass spectrometry and Cr with positive thermal ionization-mass spectrometry. The decomposition of the polymer matrix was carried out using a high pressure asher. Reference values for amount content, traceable to the SI-system, have been obtained for these three elements in both of the polyethylene samples of PERM. For each of the certified amount content values an uncertainty budget was calculated using the method of propagation of uncertainties according to ISO and EURACHEM guidelines. The measurement procedures, as well as the uncertainty calculations, are described for all three elements. In order to keep the whole certification process as transparent as possible, the preparations of various reagents and materials as well as the sample treatment and blending are described in detail. The mass spectrometry measurements and the data treatment are also explained carefully. The various sources of uncertainty present in the procedure are displayed in the uncertainty budgets. The obtained combined uncertainties for the amount content values were less than 2% relative (k=1) for all investigated elements. The amount contents were in the μmol/kg range, corresponding to mg/kg levels. Received: 21 October 1999 / Accepted: 29 January 2000     

蔬菜中苯甲酰脲类药物残留的测定方法研究

建立了一步有机溶剂提取、HPLC分离、紫外检测器检测7种苯甲酰脲类药物(除虫脲、灭幼脲、杀铃脲、氟铃脲、氟苯脲、氟虫脲和氟啶脲)在蔬菜中残留量的方法。考察了不同提取溶剂(乙酸乙酯和乙腈)的提取效率;研究了不同C18固相萃取小柱、活性碳、自制弗罗里硅土柱和GPC对蔬菜样品的净化效果;实验了不同的梯度淋洗程序分离7种药物。通过对黄瓜、大白菜、西红柿和包心菜4种蔬菜的4种添加水平和4次重复性实验,建立了一种以乙腈为提取溶剂和以弗罗里硅土柱为净化柱的高效液相色谱法测定7种苯甲酰脲类药物。该方法线性范围为:0.02~1.5mg/L,7种苯甲酰脲类药物的相关系数均大于0.999,其检出限为0.02~0.05mg/kg(S/N=10);在0.05~1.0mg/kg之间的添加回收率为80%~120%;相对标准偏差小于15%。方法完全符合残留分析的要求。     

Contribution to the certification of B, Cd, Mg, Pb, Rb, Sr, and U in a natural water sample for the International Measurement Evaluation Programme Round 9 (IMEP-9) using ID-ICP-MS

 The present paper describes the contribution of the Institute for Reference Materials and Measurements to the certification of B, Cd, Mg, Pb, Rb, Sr, and U amount contents in a natural water sample, in round 9 of the International Measurement Evaluation Programme (IMEP-9). The analytical procedure to establish the reference values for B, Cd, Mg, Pb, Rb, Sr, and U amount contents was based on isotope dilution inductively coupled plasma-mass spectrometry used as a primary method of measurement. Applying this procedure reference values, traceable to the SI, were obtained for the natural water sample of IMEP-9. For each of the certified amount contents presented here a total uncertainty budget was calculated using the method of propagation of uncertainties according to ISO and EURACHEM guidelines. The measurement procedures, as well as the uncertainty calculations are described for all seven elements mentioned above. In order to keep the whole certification process transparent and so traceable, the preparations of various reagents and materials as well as the sample treatment and blending, the measurements themselves, and finally the data treatment are described in detail. Explanations focus on Pb as a representative example. The total uncertainties (relative) obtained were less than 2% for all investigated elements at amount contents in the pmol/kg up to the high μmol/kg range, corresponding to low μg/kg and mg/kg levels. Received: 21 October 1999 / Accepted: 29 January 2000     

Feasibility studies for the preparation and certification of reference materials Part II: mineral oil contaminated waste materials

The 2-year international joint project HYCREF (Contract-No. G6RD-CT-2002-00854), funded by the European Commission in the 5th Framework programme, aimed to develop methods to prepare homogenous and stable water-, soil- and waste reference materials contaminated with mineral oil hydrocarbons and to test certify the mineral oil content by gas chromatographic methods. As mineral oil products are important sources for environmental contaminations, appropriate reference materials certified by using the new gas chromatographic methods (soil: ISO/FDIS 16703, waste: prEN 14039 and KW/04, water: ISO 9377-2) are highly needed. Additional to the HYCREF-results presented in part I–mineral contaminated soils–this second paper gives an overview of the feasibility study for the preparation and test certification of three waste reference materials (offshore marine sediment, building material and industrial waste). The following specifications, which had been defined in the project work plan, were reached successfully: uncertainty of the mineral oil content resulting from the certification exercise ≤5% and a between-bottle inhomogeneity of ≤3%. All three materials have been evaluated for long- and short term stability. They contain different levels and types of mineral oil and cover the full application range of ISO/FDIS 16703 and prEN 14039 (100–10,000 mg/kg). The expanded uncertainties U _cert of the three materials are about 6%. In this way, they are comparable to ERM^®-CC015a (U _cert=7.1%, mineral oil in a river sediment) and are suited to close the present gap of commercially available CRM for mineral oil determination in waste.     

Contribution to the certification of B,Cd, Cu,Mg and Pb in a synthetic water sample,by use of isotope-dilution ICP-MS,for Comparison 12 of the International Measurement Evaluation Programme

The contribution of the Institute for Reference Materials and Measurements to the certification of the B, Cd, Cu, Mg, and Pb content of a synthetic water sample used in Comparison 12 of the International Measurement Evaluation Programme (IMEP-12) is described. The aim of the IMEP programme is to demonstrate objectively the degree of equivalence and quality of chemical measurements of individual laboratories on the international scene by comparing them with reference ranges traceable to the SI (Système International d'Unités). IMEP is organized in support of European Union policies and helps to improve the traceability of values produced by field chemical measurement laboratories. The analytical procedure used to establish the reference values for the B, Cd, Cu, Mg, and Pb content of the IMEP-12 sample is based on inductively coupled plasma-isotope-dilution mass spectrometry (ICP-IDMS) applied as a primary method of measurement. The measurements performed for the IMEP-12 study are described in detail. Focus is on the element boron, which is particularly difficult to analyze by ICP-MS because of potential problems of low sensitivity, high mass discrimination, memory effects, and abundance sensitivity. For each of the certified amount contents presented here a total uncertainty budget was calculated using the method of propagation of uncertainties according to ISO (International Organization for Standardization) and Eurachem guidelines. For all investigated elements with concentrations in the low micro g kg(-1) and mg kg(-1) range (corresponding to pmol kg(-1) to the high micro mol kg(-1) level), SI-traceable reference values with relative expanded uncertainties ( k=2) of less than 2 % were obtained.     

实验室从ISO/IEC指南25-1990质量体系向ISO/IEC 17025-1999质量体系的过渡

对ISO/IEC17025-1999和ISO/IEC指南25-1990进行了比较，分析了ISO/IEC17025-1999的显著变化，提出了由ISO/IEC指南25-1990质量体系向ISO/IEC17025-1999质量体系过渡的措施。     

Implementation of ISO 9001 in a medical testing laboratory

 The Department of Clinical Chemistry and Molecular Genetics, within the Institute of Clinical Pathology and Medical Research at Westmead Hospital, is a medical testing laboratory operating within the public sector health system of New South Wales, Australia. It provides acute-care pathology services to Westmead Hospital (a 900-bed tertiary referral university teaching hospital) as well as to three district hospitals and three rural hospitals. In addition to these core clinical chemistry services, it offers approximately 150 specialised biochemistry, pharmacology, toxicology, trace metal and molecular genetics assays as a reference laboratory service. In 1993, the Department became Australia's first medical testing laboratory to be registered to ISO 9001-1987/AS3901-1987. In 1995, this certification was extended to AS/NZS ISO 9001-1994. We are currently preparing for further accreditation to ISO/IEC Guide 25-1990, with additional supplementary requirements for medical testing. This paper describes the Quality System that the Department developed and which has been successfully maintained and extended since original certification. Important features of the Quality System are: 1. Primary design of the Quality System to meet medical and customer needs, with subsequent addition of required ISO elements. 2. Use of national Quality Award criteria to identify key business processes. 3. Development of integrated technical non-conformance, customer complaint, staff suggestion, and quality system corrective action procedures. 4. Implementation without external resources. Our conclusions are that ISO 9000 Quality Systems can be applied to medical testing laboratories, and can be implemented with minimum resource costs. Improvements in technical and service quality and business performance have resulted from this process. However, implementation of ISO 9000 at the level of individual Departments is not ideal. Greater improvements are possible when this process is undertaken at the level of the entire organisation. Received: 9 September 1996 Accepted: 5 October 1996     

符合ISO/IEC指南25-1990的实验室质量体系向ISO/IEC 17025-1999标准过渡的文件修改

按照ISO／IEC指南25－1990建立起较完善的质量体系的实验室,可通过对质量体系文件进行适当增补或少量删减,以实现向ISO／IEC 17025－1999标准的过渡。对质量手册,按照ISO／IEC指南25－1990的13个要素逐个讨论了具体的增删内容;对程序文件,则按ISO／IEC 17025－1999要求逐个列出了应有的程序。     

Development and validation of an agar diffusion assay for determination of ceftazidime in pharmaceutical preparations

Ceftazidime (CFZ) is a broad spectrum parenteral beta-lactam antibiotic of the cephalosporin family. This paper reports the development and validation of an agar diffusion microbiological assay using the cylinder-plate method for determination of CFZ in powder for injection. The validation carried out yielded good results in terms of linearity, precision, accuracy, selectivity, and robustness. The assay is based on the inhibitory effect of CFZ upon the strain of Pseudomonas aeruginosa ATCC 27853 used as the test microorganism. The results of the assays were treated statistically by analysis of variance and were found to be linear (correlation coefficient = 0.999998) in the selected range of 8.0-32.0 microg/mL; precise [repeatability: relative standard deviation (RSD) = 1.11%; intermediate precision: between-day RSD = 1.37% and between-analyst RSD = 1.41%]; and accurate. The selectivity of the bioassay was evaluated by analysis of degraded samples at 50 degrees C, and the results were compared with a pharmacopeial liquid chromatographic method at the time 0, 24, and 48 h. The results demonstrated the validity of the proposed bioassay, which allows reliable quantitation of CFZ in pharmaceutical samples and can be used as a useful alternative methodology for CFZ analysis in routine quality control.     

k0-NAA, a valuable tool for reference-material producers.

The main concern of producers of certified reference materials (CRM) is the preparation of high-quality products with demonstrated homogeneity and stability, combined with a well established set of certified characteristics. CRM producers must, furthermore, comply with other constraints imposed by the ISO Guide 34: production processes, production control, and certification analyses should be performed by expert laboratories, using validated protocols documented in their respective quality assurance manuals; laboratory mean values and the corresponding "expanded" uncertainties, must be used for the determination of the certified values, as recommended by the ISO Guide to the Expression of Uncertainties in Measurements (GUM); and when possible, traceability of the certified value to the SI units, using appropriately validated and/or primary methods, must be ensured. k0-NAA, i.e. neutron activation analysis with k0 standardization, is one of the analytical techniques implemented at the Reference Material Unit of IRMM; it meets the first two requirements.