Bitki koruma ürünlerinin kalıntı analizlerinde temel laboratuvar işlemlerinin ölçüm belirsizlikleri

Bitki koruma ürünlerinin (pestisit) kalıntı analizlerinde, analiz sonuçlarının güvenirliği kalite güvence(QA) ve kalite kontrol(QC) parametreleri ile ispatlanmalıdır. Bu parametrelerden en önemlilerinden biri de laboratuvardaki işlemlerin ölçüm belirsizliğidir. “Uluslararası Standart Organizasyonu (ISO) 17025”, “ISO Ölçüm Belirsizliği Açıklama Kılavuzu (GUM)” ve “EUREACHEM/CITAC Guide CG4” gibi uluslararası dokümanlara göre, temel laboratuvar işlemlerinin belirsizliklerinin ölçülmesi bir zorunluluktur. Analizlerdeki ölçümler her zaman tam ve kesin değildir ve bu kesin olmamanın (belirsizliklerin) derecesinin rakamsal olarak ifade edilmesi gerekir. Ölçüm belirsizliği bir ölçümün sonucu ile ilgili olası dalgalanmaları tanımlayan istatistiksel parametredir. Analizle ilgili her bir laboratuvar islemlerinin ve prosedurlerinin belirsizliğinin saptanarak ve daha sonra da birlestirilmis toplam belirsizlik hesaplanması ile bulunabilir. Bu makale, güncel literatür taranarak, analiz islemlerine girmeden, isin baslangıcında, basit fakat etkisi önemli olan tartımsal ve hacimsel işlemler ile bunlarla ilgili diğer bazı temel laboratuvar islemlerinin belirsizliğinin “bireyselden-tüme” yaklaşımı ile saptanması ile ilgilidir.

Uncertainty measurement of basic laboratory operations in the residue analysis of plant protection products

In residue analysis of plant protection products (pesticide), the reliability of analytical results have to be proved with the quality assurance (QA) and quality control (QC) parameters. One of the most important of these parameters is the uncertainty in the measurement of basic laboratory operations. According to documents like“International Organisation for Standardisation (ISO) 17025”, “ISO Guide to the Expression of Uncertainty in Measurement (GUM)”, and “EUREACHEM/CITAC Guide CG4” (A Focus for Analytical Chemistry in Europe/The Cooperation on International Traceability in Analytical Chemistry), the uncertainty of measurements in basic laboratory operations should be estimated. Measurement results in the laboratory are not always certain, and the degree of these uncertainties have to be figured out numerically Measurement uncertainty is a statistical parameter which describes the possible fluctations of a measurement results. It can be determined by the estimation uncertainty of individual components of any operation and test procedure, and later by the calculations of combined total uncertainty. Basing on uptodate references, this article deals, without touching analytical operations, with the estimation of uncertainty of basic laboratory operations such as weighing and volumetric equipment, and some other related operations, by using “bottom-up” approaches.

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