Inexpensive and versatile method for trace Sn(II) and Sn(IV) ions in food samples by CPE/FAAS

In this work, a new cloud point extraction procedure was developed for the separation and preconcentration of tin ions in water and food samples. The method is based on the complexation of Sn(IV) ions with calcon carboxylic acid (CCA) in the presence of the non-ionic surfactant. The enriched analyte ions were determined by flame atomic absorption spectrometry. The proposed method is very versatile and economic, because it is used conventional FAAS. A preconcentration factor of 100 and detection limit of 2.86 μg L−1 were obtained from the calibration curve constructed in the range of 10–1300 μg L−1 with a correlation coefficient of 0.9978. The method was successfully applied for determination of tin ions in certified reference materials (CRMs) (TMDA 53.3, TM 25.3, ERM-BCO84a and SRM 1548a) as well as natural spring water, canned foods and fruit juices. The method was statistically validated by comparing the results obtained with those provided by application of ICP-AES technique.