Detection limit of lead and cadmium in food by graphite furnace atomic absorption spectrometry

OBJECTIVE To determine method limit of detection(LOD)and limit of quantitation(LOQ)of lead and cadmium in food by graphite furnace atomic absorption spectrometry.METHODS Based on the method of determining and calculating detection limit by International Union of Pure and Applied Chemistry(IUPAC),the LOD and LOQ of lead and cadmium in grain,meat and vegetables were determined by using different graphite furnace atomic absorption spectrophotometers.The influencing factors for the detection limit were discussed.RESULTS The LOD and LOQ of lead and cadmium for grain,meat and vegetables were different by using different graphite furnace atomic absorption spectrophotometers.Sample,sample quantity,analytical instrument,measurement conditions,analytical method,graphite cuvette,injection volume,purity of reagent and water,working curve and analyzer could influence the LOD and LOQ.CONCLUSION LOD and LOQ depend on the whole analytical process,and they are associated with the blank value,precision and sensitivity.