Egg samples were collected at the farm layerim mediately after
egg laying and then immediately transported to the laboratory.The
eggs were broken,and the albumen was separated from the yolk
with a house hold yolk separator.For amine extraction,3 g of yolk
samples and 3 g of albumen samples were weighed in 50-mL poly-
propy lenecentrifuge tubes,and 7mLoftrichloroaceticacidat
50 gL1 (50 gL1 TCA)wasadded.Thetubeswereagitatedfor
10mininaThermolynetype50800orbitalshaker(Barnstead
Thermolyne,Iowa,USA)at225rpmandthencentrifuged(12,100g)
at 4 °C for21mininachilledBeckmanJ2MCcentrifuge(Beckman
CoulterInc.,California,USA).Aftercentrifugation,thesupernatant
was filteredthroughqualitative filterpaper.Theprocedurewas
repeatedtwomoretimeswiththeadditionof7mLand6mLof
50 gL1 TCAinatotalof20mLofaddedacid.Theresultingextracts
werestoredin0.5mLmicrotubesandfrozenat 20 °C forlater
derivatizationandchromatographicanalysis.