Comparison of 4 analytical techniques based on atomic spectrometry for the determination of total tin in canned foodstuffs
International audience ; Different techniques for the determination of total tin in beverage and canned food by atomic spectrometry were compared. The performance characteristics of Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Hydride Generation Inductively Coupled Plasma Atomic Emission Spectrometry (HG-ICP-AES), Electrothermal Atomization Atomic Absorption Spectrometry (ETA-AAS) and Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) were determined in term of linearity, precision, recovery, limit of detection, decision limit (CCα) and detection capability (CCβ) (Decision 2002/657/EC). Calibration ranges were covered from ng/L to mg/L level. Limits of detection ranged from 0.01; 0.05; 2.0; 200 µg/L were respectively reached for ICP-MS; HG-ICP-AES; ETA-AAS and ICP-AES. Precision, calculated according to ISO 5725-2 for repeatability and within lab-reproducibility and expressed as relative standard deviation (RSD), ranges from 1.6 to 4.9% and recovery, based on the decision 2002/657/EC, was found between 95 to 110%. Procedures for the mineralization or extraction of total tin were compared. Wet digestion, sequentially, with nitric acid and hydrogen peroxide provided the best results. The influence of possible interferences present in canned food and in beverage was studied and no interference on the determination of tin was observed. Since maximum levels for tin established by the European legislation vary from 50 mg/kg in canned baby foods, infant food to 200 mg/kg in canned food, ICP-AES was chosen as the preferred technique for routine analysis thanks to its good precision, reliability and easy to use. The accuracy of this routine method was confirmed by participating in 6 proficiency test schemes with z-scores ranging from -1.9 to 0.6. Several canned foodstuffs and beverage samples from local market were analysed with this technique.