Agilent 5900

Following first X-ray, we collected six subsamples, each of ca. 5 g wet weight (w.w.), at random from different locations in the package and pooled them to give a single sample of ∼30 g for each of the packages of wet products tested. Samples were examined macroscopically to remove whole shot. Samples were weighed, dried to constant mass and milled. Complete air-dried products were dried to constant mass before taking a sample for milling. From each milled sample, 0.4 g was digested in nitric acid and samples, certified reference material and blanks were analysed using an inductively coupled plasma optical emission spectrometer (ICP-OES; Agilent 5900). The limit of detection (LOD) for the method for lead was 0.180 ppm dry weight (d.w.) and 0.058 ppm w.w.
Lead concentrations are given as d.w. unless otherwise stated. For raw pheasant dogfood products, on average 1 ppm w.w. = 2.76 ppm d.w.

The rats were sacrificed as described above, the brains were weighed, and immediately frozen and stored at −80 °C. Brain homogenates were digested in HNO₃ at 160 °C for 3 h. All measurements were performed by ICP-OES (Agilent 5900; Agilent Technologies, Santa Clara, CA, USA) with nebulizer, plasma, and aux flow rates of 0.7, 12, and 1 L/mL, respectively. The operation conditions were adjusted for optimal determination. Calibration curves were prepared separately by running suitable concentrations of standard solutions. Control blanks were also prepared and analyzed in the same manner. The average values of six replicates were obtained and the zinc concentration was calculated in μg/g of dry mass.