Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids we...Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).展开更多
Based upon the standard deviations for the intercept and the slope of a linear regression line, as well as by differentiating both Beer＇s law and a linear relationship between transmittance and concentration at high ...Based upon the standard deviations for the intercept and the slope of a linear regression line, as well as by differentiating both Beer＇s law and a linear relationship between transmittance and concentration at high transmission, it is proved that the relative spectrophotometric error of a measurement becomes greater as the sample concentration only decreases. Further, it is demonstrated that the present knowledge with regard to the error in absorption spectrophotometry is necessary to be reexamined. The total scale of transmittance can literally be used for measurements, unfolding workable dynamic ranges about two orders of magnitude lower than usually and thus absorption spectrophotometry can efficiently compete with other methods of analysis with respect to detection limits.展开更多
文摘Egg yolk phosphatidylcholine(EYPC) is being widely used in food and pharmaceutical industries nowadays owing to its surface activity,pharmaceutical usefulness,and so on.Common determination methods of phospholipids were based on the American Oil Chemists' Society(AOCS) Official Method Ja7b-91,in which n-hexane/2-propanol/acetate buffer was used as the mobile phase.In order to achieve desired results,gradient elu-tion or buffer solution was used,which made the detection process more complicated.Moreover,water or buffer solution could affect the silica gel column both on its lifespan and the separation efficiency significantly.In this study,different mobile phase and detector were used to simplify EYPC analyzing process instead of using water within the mobile phase.The optimized HPLC operating conditions are as follows:pure methanol as a mobile phase,flow rate of 1.0 ml·min-1,silica gel column(250 mm×4.6 mm,5 μm,Inertsil GLTM),column temperature 30 ℃ and low temperature evaporative light scattering detector(40 ℃,0.35 MPa) as used.Under this optimal condition,the linear relative coefficient of the standard curve is 0.998 and the recovery was in the range of 96.83%-101.58% with a relative standard deviation of 1.79%(n=6).
文摘Based upon the standard deviations for the intercept and the slope of a linear regression line, as well as by differentiating both Beer＇s law and a linear relationship between transmittance and concentration at high transmission, it is proved that the relative spectrophotometric error of a measurement becomes greater as the sample concentration only decreases. Further, it is demonstrated that the present knowledge with regard to the error in absorption spectrophotometry is necessary to be reexamined. The total scale of transmittance can literally be used for measurements, unfolding workable dynamic ranges about two orders of magnitude lower than usually and thus absorption spectrophotometry can efficiently compete with other methods of analysis with respect to detection limits.
