Egg yolk Se analysis

Three eggs per replicate sampled at 12 wk were pooled for Se determination in egg yolks. Pooled egg yolks were homogenized, frozen immediately at −20°C, and lyophilized (Labtech Freeze Dryer; Daihan, Namyangju, Korea) at −80°C. After lyophilization, the samples were ground for Se analysis. Approximately 0.5 g of sample was digested with 2.5 mL of HNO₃ in a microwave digestion system (Multiwave 7000; Anton Paar, Graz, Austria), and the Se content of the wet-digested sample was determined by inductively coupled plasma-optical emission spectrometry (Avio 200; Perkin Elmer, Waltham, MA, USA) [22].