Determination Of Sudan Red,Melamine And Fatty Acid In Egg

Eggs,which contain rich nutrient compositions,have become an indispensable component part of people's diet in daily life.It is important to detect the the beneficial and harmful substances in eggs.In the study,we successfully developed several methods for determination of Sudan Red,melamine and fatty acids in egg samples.This thesis included the following parts:(1)The content of Sudan I,II,III,IV in 3 kinds of egg samples were determined by matrix solid-phase dispersion and high-performance liquid chromatography(MSPD-HPLC).The Sudan dyes was extracted by silica gel as dispersant and ethyl acetate as eluent.The detection limits of Sudan I,II,III,IV were 3.2,5.4,5.3 and 7.8 ?g/kg,respectively.Three kinds of egg samples were determined,and the standard recovery rate was 79.8-95.0%,and the RSDs was 2.3-9.1%.The method was fast,sensitive and simple,could be used to determination of Sudan I,II,III and IV in egg.(2)The content of melamine in 3 kinds of egg egg samples were determined by surface enhanced Raman spectroscopy(SERS).The determination of melamine can be completed within 5 min by using 0.2 mL silver nanosol as enhancement reagent,0.15 mL 0.5 mol/L NaCl solution as sedimentation agent,and 0.2 mL 1.0 mol/L NaOH solution as acidity regulator.The limit of detection was 3.0 ?g/L,and the detection range was 0.010-5.0 mg/L.Three kinds of egg samples were determined,and the standard recovery rate was 96-106%,and the RSDs was 2.6-4.7%.The method was simple and accurate,and can be used to determination of melamine in egg.(3)The fatty acids in yolk of 6 kinds of eggs were detected by gas chromatography-mass spectrometry(GC-MS).The fatty oil in yolk was extracted by bligh-dyer method and the fatty acids were analyzed by GC-MS.The results showed that 18 fatty acids were identified in ordinary egg,including 8 kinds of saturated fatty acids and 10 unsaturated fatty acids.19 fatty acids were identified in native egg,including 10 kinds of saturated fatty acids and 9 unsaturated fatty acids.16 fatty acids were identified in fuxi egg,including 8 kinds of saturated fatty acids and 8 unsaturated fatty acids.21 fatty acids were identified in naohuangjin egg,including 9 kinds of saturated fatty acids and 12 unsaturated fatty acids.17 fatty acids were identified in dark egg,including 8 kinds of saturated fatty acids and 9 unsaturated fatty acids.21 fatty acids were identified in qianbaihe egg,including 11 kinds of saturated fatty acids and 10 unsaturated fatty acids.This method could be used to determine the fatty acids in yolk of eggs.