Determination of lead in shellfish by ultrasound assisted extraction-atomic absorption spectrometry with response surface method

The optimized extraction conditions of lead in shellfish were obtained by Plackett-Burman design and response surface methodology on the basis of single factor experiment. The results indicated that the extraction rate of lead was 93.0%when ultrasonic extraction time was 29 min, ultrasonic temperature was 40 ℃, ultrasonic power was 320 W, HNO3 ( 2.5 mol/L) -H2O2 ( 3 mol/L) 8.10 m L.The relative standard deviation was 5.83%, the limit of detection was 0.65 μg/L, limit of quantity was2.1 μg/L.The results of t test showed that there was no significant difference between the ultrasound assisted extraction and wet digestion method.The ultrasonic extraction is more convenient, safer and can also be applied to determination of lead in shellfish.