Occurrence of aflatoxins in peanuts and peanut products determined by liquid chromatography with fluorescence detection

Abstract

Liquid chromatography with fluorescence detection using immunoaffinity column clean-up was a method described for determination of aflatoxins (AFB1, AFB2, AFG1 and AFG2) in peanuts and peanut based products. The validation of the procedure was performed. Good coefficient of correlation was found for all aflatoxins in the range of 0.9993-0.9999. Limit of detection (LOD) and limit of quantification (LOQ) ranged from 0.003-0.005 mg/kg and 0.009-0.023 mg/kg, respectively, which was acceptable. The mean recovery for total aflatoxins was 88.21%. The method also showed acceptable precision values in the range of 0.171-2.626% at proposed concentration levels for all four aflatoxins. RSDR values (within laboratory reproducibility) calculated from the results showed good correlation between two analysts for all aflatoxins and they ranged from 4.93-11.87%. The developed method was applied for the determination of aflatoxins in 27 samples of peanuts and peanut based products. The results showed that 21 peanut samples (77.7%) were below LOD of the method. Three samples had positive results over the MRL. There was one extreme value recorded for the total aflatoxins in peanut (289.2 mg/kg) and two peanut based products, peanut snack and peanut, with total content of aflatoxins being 16.3 mg/kg and 8.0 mg/kg, respectively. The obtained results demonstrated that the procedure was suitable for the de?termination of aflatoxins in peanuts and peanut based products and it could be implemented for the routine analysis.U radu je opisan metod za odredjivanje aflatoksina (AFB1, AFB2, AFG1 i AFG2) u kikirikiju i proizvodima od kikirikija primenom metoda tecne hromatografije sa fluorescentnim detektorom uz primenu imunoafinitetne kolone za preciscavanje. Takodje je prikazan i postupak validacije metoda. Za sve ispitivane aflatoksine, pokazan je dobar koeficijent korelacije koji se kretao u opsegu 0.9993-0.9999. Limit detekcije (LOD) i limit kvantifikacije (LOQ) se kretao u prihvatljivim granicama od 0.003-0.005 mg/kg i 0.009-0.023 mg/kg, respektivno. Srednja vrednost za rikaveri za sumu aflatoksina je bio 88.21%. Metod je takodje pokazao zadovoljavajucu preciznost za ispitivanje koncentracija toksina i kretao se u opsegu 0.171-2.626%. Intralaboratorijska reproduktivnost (RSDr) je pokazala dobru korelaciju izmedju dva analiticara za sve ispitivane aflatoksine i kretala se u granicama 4.93-11.87%. Ispitivan metod je primenjen u odredjivanju sadrzaja aflatoksina u 27 uzoraka kikirikija i proizvoda od kikirikija. Rezultati ispitivanja su pokazali da je sadrzaj aflatoksina u 21 uzorku (77.7%) bio ispod limita detekcije (LOD) metoda. Tri uzorka su bili pozitivni na sadrzaj toksina i sadrzali su ih u dozi visoj od maksimalno dozvoljenih vrednosti. Postojao je jedan uzorak kikirikija sa ekstremno visokim sadrzajem aflatoksina (289.2 mg/kg) i dva proizvoda na bazi kikirikija (kiki?riki snek) sa ukupnim sadrzajem aflatoksina od 16.3 mg/kg i 8.0 mg/kg. Rezultati potvrdjuju da je prikazan metod odgovarajuci za odredjivanje aflatoksina u kikirikiju i srodnim proizvodima i preporucuje se njegova primena u rutinskim analizama.