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90Sr is considered as a dangerous contaminant of agri-food supply chains due to its chemical affinity with Calcium, which makes its absorption in bones easy. 90Sr accumulation in raw materials and then in final products is particularly significant in relationship to its ability to transfer into animal source products. The radionuclides transfer (137Cs and 90Sr) from environment to forages and then to products of animal origin (milk, cow and pork meats) was studied and evaluated in different studies, which were carried out in contaminated areas, from Chernobyl disaster until today. In the present work, the development and validation of a radiochemical method for the detection of 90Sr in different types of animal feed, and the application of this technique for routinely control activities, are presented. Liquid scintillation counting was the employed analytical technique, since it is able to determine very low activity concentrations of 90Sr (<0.01 Bq Kg–1). All samples analysed showed a 90Sr contamination much higher than method detection limit (0.008 Bq kg–1). In particular, the highest mean activity concentration was registered in hay samples (2.93 Bq kg–1), followed by silage samples (2.07 Bq kg–1) and animal feeds (0.77 Bq kg–1). In fact, all samples were characterized by 90Sr activity concentrations much lower than reference limits. This notwithstanding, the necessity to monitor these levels was confirmed, especially considering that 90Sr is a possible carcinogen for human.

Strontium-90 is a hazardous radionuclide derived from nuclear fission processes, and it decays emitting high-energy beta-particles forming yttrium-90. It may be easily absorbed in humans through several food supply chains, since it is chemically similar to some important biological elements such as potassium and calcium. In this work an analytical method for the determination of radiostrontium in milk by liquid scintillation counting was developed in order to obtain a precise quantification at low activity concentration levels. Moreover, a full validative approach was applied to confirm method reliability. Good analytical performance was obtained by developing an in-house validation model according to Regulation 882/2004/EC and Decision 657/2002/EC with a good selectivity, a decision threshold and detection limit corresponding to 0.003 and 0.006 Bq l⁻¹ (α = β = 0.05) respectively, a repeatability value, expressed as CV%, equal to 13%, a mean recovery value equal to 102.5% and a measurement uncertainty equal to 11.5%. Strontium and yttrium chemical yields were determined by a reliable analytical method by inductively coupled mass spectrometry, assuring a suitable correction of final result. The results of the method validation, combined with a quality control assurance, performed on a reference material, demonstrated that the procedure represents a substantial improvement in the determination of ⁹⁰Sr relating to accurate confirmation analyses.

Summary The aim of this study was to develop and validate an efficient analytical method based on gas chromatography/tandem mass spectrometry (GC/MS/MS) for detection and quantification of six pyrethroids residues (Phenothrin, Permethrin, Cyfluthrin, Cypermethrin, Deltamethrin and Fenvalerate) in chicken eggs. The method was based on a preliminary liquid–liquid extraction of albumen‐free yolk samples, followed by a clean‐up by solid‐phase extraction. GC/MS/MS analyses were carried out in the selected reaction monitoring mode. Validation parameters such as specificity, detection capability, decision limit, precision, recovery, stability and ruggedness were determined, resulting in compliance with Decision 2002/657/EC. No complicated apparatus are required; moreover, low volumes of organic solvents and a nonintensive manual labour are required. These low costs and simple procedure, based on rapid and safe operations, may represent a useful tool in the routine analysis of pyrethroids pesticides, in the place of the currently used conventional techniques.