Iranian Research Organization for Science and Technology (IROST) Innovative Food Technologies 2783-350X 3 3 2016 05 21 Ultra trace determination of lead and cadmium in pasteurized and sterilized milk by dispersive liquid–liquid microextraction based on solidification of floating organic drop using electro thermal atomic absorption spectrometry Ultra trace determination of lead and cadmium in pasteurized and sterilized milk by dispersive liquid–liquid microextraction based on solidification of floating organic drop using electro thermal atomic absorption spectrometry 99 109 303 10.22104/jift.2016.303 FA Somayeh Esfandiary Master of Science, Department of chemistry and food engineering, Maragheh branch, Islamic Azad University, Maragheh, Iran Hossein Sheikhloie Assistant Professor, Department of chemistry and food engineering, Maragheh branch, Islamic Azad University, Maragheh, Iran Journal Article 2016 04 05 In this research, a simple and efficient method known as dispersive liquid–liquid  microextraction based on solidification of floating organic drop combined with electro thermal  atomic absorption spectrometry was developed for extraction and determination ultra-trace amounts of lead and cadmium in pasteurized and sterilized milk samples. Some effective factors that influence the microextraction efficiency such as; pH, type and volume of disperser solvent, extraction solvent, concentration of chelating agent, salt effect, centrifuging condition, extraction time and temperature were investigated and optimized. Under the optimal conditions, the limits of detection were obtained 0.1 ng mL^-1 for lead, 0.3 ng mL^-1 for cadmium and preconcentration factor was 100. The relative standard deviations of Lead and cadmium (n=5) 1.33% and 1.7% were observed respectively. The results showed that the amount of lead and cadmium in pasteurized and sterilized milk has been in the range of international standards, and no risk of heavy metals in the body of milk consumers. The main advantages of proposed method was simple, low cost, rapid, recovery and high extraction efficiency, good reproducibility, minimum organic solvent consumption and efficient analytical method for the separation and  determination of lead and cadmium in water and milk samples. In this research, a simple and efficient method known as dispersive liquid–liquid  microextraction based on solidification of floating organic drop combined with electro thermal  atomic absorption spectrometry was developed for extraction and determination ultra-trace amounts of lead and cadmium in pasteurized and sterilized milk samples. Some effective factors that influence the microextraction efficiency such as; pH, type and volume of disperser solvent, extraction solvent, concentration of chelating agent, salt effect, centrifuging condition, extraction time and temperature were investigated and optimized. Under the optimal conditions, the limits of detection were obtained 0.1 ng mL^-1 for lead, 0.3 ng mL^-1 for cadmium and preconcentration factor was 100. The relative standard deviations of Lead and cadmium (n=5) 1.33% and 1.7% were observed respectively. The results showed that the amount of lead and cadmium in pasteurized and sterilized milk has been in the range of international standards, and no risk of heavy metals in the body of milk consumers. The main advantages of proposed method was simple, low cost, rapid, recovery and high extraction efficiency, good reproducibility, minimum organic solvent consumption and efficient analytical method for the separation and  determination of lead and cadmium in water and milk samples. https://jift.irost.ir/article_303_11b9842e0a271ff252c1903e7132cd68.pdf