engleski

Method optimization for fatty food sample preparation for GC-ECD analysis of organochlorine pesticides

Fatty foods are a complex matrix and it is very challenging to find an appropriate method of sample preparation that can obtain extracts with a minimum proportion of interference. Gel permeation chromatography (GPC) has proven to be the most effective method for purifying fatty food samples in the past. More recently, as an alternative to the GPC method, the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) method has gained popularity. At the Andrija Štampar Teaching Institute of Public Health, the method for fatty food samples preparation for analysis of 29 organochlorine pesticides by gas chromatography with an electron capture detector (GC-ECD) was optimised. The method is based on the extraction of samples with acetonitrile and purification through two dispersive solid phase extraction (dSPE) columns [Enhanced Matrix Removal_Lipid (EMR_Lipid) and EMR Polish] that removes fat and water from the samples. To increase the extraction efficiency of the pesticide, acetonitrile : ethyl acetate=80:20 was used instead of pure acetonitrile. The method was validated where the matrix influence, sample preparation repeatability, influence of evaporation extract to dryness, limits of quantification, and recovery were examined. Acceptance criteria for validation experiments were taken from document SANTE/12682/2019. By validating the method, satisfactory results were achieved for linearity (k >0.98), repeatability of sample preparation (RSD <20 %), limit of quantification (0.005 mg/kg) and recovery (40- 140 %). Given the results obtained and a satisfying proficiency testing result (EUPT AO15 ; z score <l±2l for rapeseed oil), the method is suitable for routine analysis of fatty food samples with a fat content >30%.

Analytical validation ; Dispersive solid phase extraction ; Enhanced matrix removal ; QuEChERS ; SANTE

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