Validation of HPLC analytical method for determination of nitrates in vegetables

U ovom radu su određivani nitrati u povrću HPLC analitičkom metodom. Nitrati su grupe spojeva koji se mogu naći u povećanoj koncentraciji u lisnatom povrću poput zelene salate i špinata. Dopuštena količina nitrata u zelenoj salati iznosi 2500–4500 mg kg-1, a kod špinata 2500–3000 mg kg-1 (Pravilnik o najvećim dopuštenim količinama određenih konatminanata u hrani, 2008). Zbog štetnog utjecaja nitrata, određivali smo njegovu maseni udio u ostalim vrstama povrća koje se učestalo konzumiraju. Postoji indikacija da povećano uzimanje nitrata/nitrita i nastanaka nitrozamina može imati za posljedicu razvoj karcinoma. U radu su određeni maseni udjeli nitrata u 16 vrsta povrća koje se učestalo koriste u prehrani u Republici Hrvatskoj. Niti u jednom povrću nije utvrđena povećana koncentracija nitrata. Također je ispitivana osjetljivost analitičke metode na promjenu temperature i vremena ekstrakcije te promjene pH pokretne faze.We used this study to determine the nitrate level in vegetables by HPLC analytical method. Nitrates are a group of compounds that are found in increased concentrations in leafy vegetables like lettuce and spinach. The permissible amount of nitrate in lettuce is 2500-4500 mg kg-1, and the spinach 2500-3000 mg kg-1 (Ordinance on maximum levels for certain food contaminants, 2008). Due to the adverse effects of nitrates, we determined its mass fraction in other types of vegetables that are commonly consumed. There are indications that increased intake of nitrate / nitrite and formation of nitrosamines may result in the development of cancer. In this work, the mass fraction of nitrate was determined in 16 types of vegetables that are commonly used in food in the Republic of Croatia. In none of vegetables was found increased concentrations of nitrate. We also examined the sensitivity of analytical methods to change the temperature and extraction time and change of pH mobile phase