VALIDATION AND MEASUREMENT UNCERTAINTY DETERMINATION OF COPPER CONTENT IN COPPER FUNGICIDES

Namen diplomske naloge je bil validirati postopek določitve masnega deleža bakra v bakrovem fungicidu Cuprablau Z s potenciometrično titracijo in izračunati merilno negotovost rezultata določitve bakra. Za validacijo tega parametra smo se odločili zato, ker je baker aktivna snov v fungicidu. Za ostale parametre (suspenzibilnost, sejalni ostanek, omočljivost in izguba pri sušenju), ki se določajo v vzorcih Cuprablau-a Z, pa smo ovrednotili samo natančnost analitskih postopkov. Pri postopku validacije metode določitve masnega deleža bakra smo preverili selektivnost, linearnost, točnost, ponovljivost in obnovljivost preskusne metode, s tem smo potrdili karakteristike zmogljivosti in omejitve preskusne metode ter identificirali vplive, ki lahko te karakteristike spreminjajo. Za preverjanje selektivnosti metode smo raziskali vpliv interferenta - železa na rezultate določitve bakra. Za oceno linearnosti smo izvedli meritve realnega vzorca z različnimi standardnimi dodatki bakra. Točnost preskusnega postopka smo preverili s preskusom izkoristka, ki smo ga izvedli na realnem vzorcu z dodatkom bakra. Za oceno ponovljivosti določitve smo izvedli ponovitve meritev pod pogoji ponovljivosti na različnih realnih vzorcih. Za oceno obnovljivosti določitve pa smo izvedli ponovitve meritev pod pogoji obnovljivosti (ponovitve v različnih časovnih obdobjih z več analitiki) na različnih realnih vzorcih. Ugotovili smo, da je postopek določitve masnega deleža bakra v bakrovem fungicidu Cuprablau Z ustrezen za predvideno uporabo. Z validacijo smo dokazali, da je preskusna metoda selektivna, linearna, točna in natančna. Z ovrednotenjem merilne negotovosti rezultata določitve bakra smo določili kakovost in lažjo primerljivost rezultatov.The purpose of this diploma thesis was to validate the process for determining the mass fraction of copper in the copper fungicide Cuprablau Z by potenciometric titration and to calculate the measurement uncertainty of the copper determination results. We decided to validate this parameter since copper is the active ingredient of the fungicide. For other parameters (suspensibility, wet sieving , wettability, and drying loss), which are determined in the samples of Cuprablau Z, we evaluated only the accuracy of analytical procedures. In the validation process of the method for determining the mass fraction of copper, we verified selectivity, linearity, accuracy, repeatability, and reproducibility of a test method, and thus confirmed properties of capabilities and limitations of the test methodbesides, we identified the impacts which can change these properties. In order to prove selectivity of a method, we explored the effect of the interferent- iron, on the results of copper determination. For estimation of the linearity, measurements of the real sample with standard addition of different copper contents were performed. The accuracy of the test procedure was examined through the recovery test carried out using a real sample by adding copper. For reproducibility estimation measurements were performed under reproducibility conditions of (replicate analyses within larger tie intervals by different analysts) on different real samples. We established that the analytical method for determination of the mass fraction of copper in the copper fungicide Cuprablau Z is suitable for its intended use. Through validation we have shown that the test method is selective, linear, precise, and accurate. By evaluating the measurement uncertainty of the result of copper determination, the quality and easier comparability of results have been established