Validation of an analytic method for determination of citrate in urine using ion chromatography

Uvod: Analiza citrata u urinu vrlo je vaţna za procjenu urolitijaze, bolesti koja je posljedica procesa patološke biomineralizacije u urotraktu koja rezultira s pojavom mokraćnih kamenaca. Cilj istraţivanja: Ciljevi predloţenog istraţivanja su provesti validaciju analitičke metode ionske kromatografije za odreĎivanje citrata u urinu te utvrditi korelaciju dobivenih rezultata odreĎivanja citrata u urinu s postojećom enzimsko-spektrofotometrijskom metodom. Nacrt istraţivanja: Presječno istraţivanje. Ispitanici i metode: U istraţivanje je ukupno bilo uključeno 50 nasumičnih uzoraka urina pacijenata s urolitijazom. Kao metode za odreĎivanje citrata korištene su postojeća enzimsko-spektrofotometrijska metoda (Olympus AU680) te metoda ionske kromatografije (Dionex ICS-3000). Rezultati: OdreĎivanjem koncentracije citrata u uzorcima urina dobiveni su rezultati od 0,16 do 6,74 mmol/l. Dobiveni koeficijent korelacije kalibracijskog pravca iznosi 0,999. Granica detekcije iznosi 0,00035 mmol/l, a granica kvantifikacije 0,001 mmol/l. Ponovljivost odreĎivanja koncentracije citrata iznosi 1,95 %. Intermedijarna preciznost u 16 dana iznosi 2,21 %. OdreĎivanjem točnosti dobiveno je iskorištenje od 99,66 %. Područje primjene nalazi se izmeĎu 0,0010 i 0,052 mmol/l. Usporedbom dviju metoda za odreĎivanje citrata dobiven je koeficijent korelacije 0,99. Passing-Bablockovom regresijom dobiven je regresijski pravac y = 1,012195x - 0,0225810, a Demingovom regresijskom analizom regresijski pravac y = 1,0177 x - 0,01611. Zaključak: ProvoĎenjem validacije metode ionske kromatografije potvrĎeno je kako se svi provedeni validacijski parametri nalaze u kriteriju prihvatljivosti, iz čega proizlazi zaključak kako je metoda primjenjiva svrsi. Uvidom u rezultate statističke obrade, moţemo uočiti kako obje metode daju jako usporedive rezultate.Introduction: Analysis of citrates in the urine is very important for the evaluation of urolithiasis, a disease that is a consequence of pathological processes of biomineralization in the urinary tract, which results in the appearance of urinary stones. Objectives: The objectives of the proposed research are to carry out validation of analytical methods for ion chromatography for the determination of citrate in the urine and to determine the correlation of the results of determination of citrate in the urine with the existing enzyme – spectrophotometric method. The research design: Cross-sectional survey. Patients and Methods: The study included a total of 50 random urine samples of patients with urolithiasis. Methods used for the determination of citrate are existing enzyme-spectrophotometric method (Olympus AU680) and method of ion chromatography (Dionex ICS-3000). Results: By determining the concentration of citrate in the urine, the results ranged from 0.16 to 6.74 mmol/l. The resulting correlation coefficient of the calibration curve is 0.999. The detection limit is 0.00035 mmol/l, and the limit of quantification of 0.001 mmol/l. Repeatability of determining the concentration of citrate is 1.95%. Intermediate precision for a period of 16 days is 2.21%. By determination, accuracy was obtained in a yield of 99.66%. Scope is between 0.0010 and 0.052 mmol/l. Comparing the two methods for the determination of citrate, the correlation coefficient is 0.99. Passing-Bablockovom regression obtained by the regression line is y = 1,012195x - 0.0225810, and Deming regression analysis regression line y = 1,0177x - 0.01611. Conclusion: The implementation of validation of ion chromatography confirmed that all the validation parameters are carried out within the eligibility criteria, which resulted in the conclusion that the method is applicable. In examination of the results of statistical analysis, we can see that both methods provide very comparable results