DETERMINATION OF ORTHOPHOSPHATE, AMMONIUM NITROGEN, MBAS INDEX AND PHENOLIC INDEX IN WATERS BY FLOW ANALYSIS

Namen diplomske naloge je bil potrditev točnosti določevanja ortofosfata, amonijakalnega dušika, MBAS indeksa in fenolnega indeksa, s pomočjo konstantnega pretočnega analizatorja, v različnih vodnih vzorcih. Z izvajanjem avtomatiziranih konstantno pretočnih analiznih metod lahko analiziramo v kratkem časovnem obdobju večje število vzorcev (npr. 50 vzorcev v pol ure). Analizne metode smo ovrednotili v skladu z dobro laboratorijsko prakso, ISO standardi in smernicami, pravili, navodili za validacijo. Pri postopku validacije smo obravnavali pripravo umeritvene krivulje, ugotavljali stabilnost sistema, točnost linearnega modela umeritvene krivulje, koeficient kvalitete, ponovljivost in obnovljivost v različnih vrstah realnih vzorcev vod. Metode smo preizkusili še z analiziranjem certificiranih referenčnih materialov in s primerjalnimi testi v različnih medlaboratorijskih shemah, kjer smo dobili zelo dobre rezultate pri vseh parametrih z odstopanji med 0 in 19 %. Iz rezultatov meritev posameznih parametrov v različnih vrstah vod smo tudi ugotovili, da so vode v Sloveniji glede na vrsto matrice in izvor dokaj čiste, razen nekaj izjem, ki so posledica onesnaženja zaradi kmetijstva, industrije ali nespametnega delovanja posameznikov.The purpose of the diploma work is a confirmation of the accuracy of the method for determination orthophosphate, ammonium nitrogen, MBAS and phenol index, using a continuous flow analysis (CFA) for various types of water samples. The use of constant flow analysis methods enable analysis of large numbers of samples in a short period of time (eg 50 samples in half an hour). Analytical methods were evaluated in accordance with good laboratory practice, ISO standards and various guidelines, rules and instructions for validation. In the validation process the preparation of calibration curve, system stability, suitability and accuracy of the linear model for calibration curve, the quality coefficient, repeatability and reproducibility in different types of real water samples were assessed. Methods accuracy was confirmed also by the analysis of certified reference materials and samples in proficiency tests from various inter-laboratory comparisons with very good results for all parameters with the deviations between 0 and 19%. The results of measurements of each parameter in different types of water show that water in Slovenia is relatively clean with respect to the nature and origin of the matrix, with some exceptions, where the contamination is a result of pollution from agriculture, industry or irresponsible action by individuals