VALIDATION AND MEASUREMENT UNCERTAINTY ESTIMATION OF PHENOL INDEX SPECTROPHOTOMETRIC METHOD (ISO 6439:1996/A) FOR LEACHING WASTE WATER FROM OLD BATTERIES

V diplomskem delu sta bili izvedeni validacija in določitev merilne negotovosti fenolnega indeksa spektrofotometrične metode s 4-aminoantipirinom s predhodno destilacijo po SIST ISO 6439: 1996 metoda A. Izlužek odpadkov je bil pripravljen s postopkom ekstrakcije, kjer odstranjujemo iz trdnih zmesi topne komponente s topilom, ki je v našem primeru voda. Odpadek je opredeljen kot nevaren odpadek, saj vsebuje težke kovine – svinec, sestavljata pa ga še polipropilen in polivinil klorid. V izlužku odpadkov izrabljenih akumulatorjev smo spremljali koncentracijo fenolnega indeksa, ki po uredbi o odpadkih ne sme presegati 100 mg/l. Validacija analizne metode je obsegala določitev merilnega območja, mejo zaznavnosti in mejo določljivosti, linearnost, natančnost meritev, točnost in vpliv interferenc. Ko so bili doseženi predpisani parametri, predvsem linearnost in točnost metode, ter so bili tudi vsi ostali parametri pod predhodno določeno mejo, je bila validacija zaključena. Ugotovili smo, da merilna negotovost znaša ± 11% odstopanja od prave vrednosti rezultata (faktor pokritja k = 2 predstavlja 95% stopnjo zaupanja) in je bila določena po modelu, ki uporablja validacijske podatke.In the thesis validation and determination of measurement uncertainty of phenol index spectrophotometric method with 4-aminoantipyrine with prior distilation by SIST ISO 6439:1996 the method A were performed. Leaching waste was prepared by the extraction procedure, where soluble components are removed from solid mixtures by the solvent, which in our case is water. The waste is considered a hazardous waste, because it contains heavy metals – lead. Mostly it contains polypropylene and polyvinyl chloride. In leaching waste from old batteries we followed concentrations of phenol index, which in accordance to the Decree on waste management should not exceed 100 mg/ l. Validation included determination of measuring range, limit of quantification and limit of determination, linearity, precision of measurements, accuracy and influence of interferences. When linearity and accuracy of the method were achieved and the other parameters were below the certain limit, the validation was completed. We found out that measurement uncertainty deviates from results for ± 11 % (the coverage factor k = 2 gives a confidence level of approximately 95 %) and was determinated by the model, which uses validation data