The rheological properties in the supernatant of peach gum from Prunnus dulcis were discussed in order to provide more scientific technical parameters and references for developing peach gum as a kind of medicinal gum...The rheological properties in the supernatant of peach gum from Prunnus dulcis were discussed in order to provide more scientific technical parameters and references for developing peach gum as a kind of medicinal gum.The rheological properties in the supernatant of peach gum were comparatively studied in different material ratios,temperatures,shaking times,pH values and salinities.The results show that,1) the mathematical model of shear rate with material ratio and shear stress is Y=0.069X12+0.035X2 -1.174,R2=0.942;2) the mathematical model of shear rate with temperature and shear stress is Y=4.936X12+0.023 2X2-1.688,R2=0.937;3) the mathematical model of shear rate with shaking time and shear stress is Y=0.005 192 X13-0.140 73X12+1.249 045X1+ 0.036 546 X2-3.644 29,R2=0.954 3;4) the effects of pH value on the rheological properties in the supernatant of peach gum are comparatively complicated with a varying range of 3-11 and the shear rate shows a change trend of saddle model;5) the mathematical model of shear rate with the concentration of NaCl and shear stress is Y=-0.037 44X1+0.012 93 X2,R2=0.998;6) the mathematical model of shear rate with the concentration of CaCl2 and shear stress is Y=0.025 789X1+0.016 19X2,R2 =0.999;and 7) the mathematical model of shear rate with the concentration of sorbic acid potassium and shear stress is Y=0.079 5X1+0.017 3X2,R2=0.998.The results show that the material ratio,temperature,shaking time,pH value significantly affect the rheological properties in the supernatant of peach gum,and the concentrations of NaCl and CaCl2 also significantly affect the rheological properties expect the concentration of sorbic acid potassium.展开更多
建立了一种μ-QuEChERS结合气相色谱-三重四极杆串联质谱仪(gas chromatography-triple quadrupole tandem mass spectrometry,GC-MS/MS)在10 min内测定桃胶中106种农药残留的方法。样品经μ-QuEChERS方法提取、净化,经超高惰性气相色谱...建立了一种μ-QuEChERS结合气相色谱-三重四极杆串联质谱仪(gas chromatography-triple quadrupole tandem mass spectrometry,GC-MS/MS)在10 min内测定桃胶中106种农药残留的方法。样品经μ-QuEChERS方法提取、净化,经超高惰性气相色谱柱(highly inert gas chromatographic column,HIGC)分离,以三重四极杆-串联质谱仪检测分析,基质标准曲线外标法定量。106种农药在0.00200~0.400 mg/kg范围,其线性相关系数R均大于0.995,对于0.500 g样品的106种农药的检出限为(5.84×10^(-6))~(2.81×10^(-3))mg/kg,定量限为(1.95×10^(-5))~(9.36×10^(-3))mg/kg,且低、中、高3个浓度添加水平的回收率为72%~109%,相对标准偏差(relative standard deviations,RSDs)为0.73%~10%。该方法具有快捷、污染小、可靠性强的特点,适用于桃胶中多种农药残留的快速定性和定量检测。展开更多
基金Project(2006BAD18B02) supported by the 11th Five-Year Plan of National Key Technology R&D Program of ChinaProject(07006B) supported by Youth Fund of Central South University of Forestry and Technology,ChinaProject(080929) supported the Education Fund of Hunan Province,China
文摘The rheological properties in the supernatant of peach gum from Prunnus dulcis were discussed in order to provide more scientific technical parameters and references for developing peach gum as a kind of medicinal gum.The rheological properties in the supernatant of peach gum were comparatively studied in different material ratios,temperatures,shaking times,pH values and salinities.The results show that,1) the mathematical model of shear rate with material ratio and shear stress is Y=0.069X12+0.035X2 -1.174,R2=0.942;2) the mathematical model of shear rate with temperature and shear stress is Y=4.936X12+0.023 2X2-1.688,R2=0.937;3) the mathematical model of shear rate with shaking time and shear stress is Y=0.005 192 X13-0.140 73X12+1.249 045X1+ 0.036 546 X2-3.644 29,R2=0.954 3;4) the effects of pH value on the rheological properties in the supernatant of peach gum are comparatively complicated with a varying range of 3-11 and the shear rate shows a change trend of saddle model;5) the mathematical model of shear rate with the concentration of NaCl and shear stress is Y=-0.037 44X1+0.012 93 X2,R2=0.998;6) the mathematical model of shear rate with the concentration of CaCl2 and shear stress is Y=0.025 789X1+0.016 19X2,R2 =0.999;and 7) the mathematical model of shear rate with the concentration of sorbic acid potassium and shear stress is Y=0.079 5X1+0.017 3X2,R2=0.998.The results show that the material ratio,temperature,shaking time,pH value significantly affect the rheological properties in the supernatant of peach gum,and the concentrations of NaCl and CaCl2 also significantly affect the rheological properties expect the concentration of sorbic acid potassium.
文摘建立了一种μ-QuEChERS结合气相色谱-三重四极杆串联质谱仪(gas chromatography-triple quadrupole tandem mass spectrometry,GC-MS/MS)在10 min内测定桃胶中106种农药残留的方法。样品经μ-QuEChERS方法提取、净化,经超高惰性气相色谱柱(highly inert gas chromatographic column,HIGC)分离,以三重四极杆-串联质谱仪检测分析,基质标准曲线外标法定量。106种农药在0.00200~0.400 mg/kg范围,其线性相关系数R均大于0.995,对于0.500 g样品的106种农药的检出限为(5.84×10^(-6))~(2.81×10^(-3))mg/kg,定量限为(1.95×10^(-5))~(9.36×10^(-3))mg/kg,且低、中、高3个浓度添加水平的回收率为72%~109%,相对标准偏差(relative standard deviations,RSDs)为0.73%~10%。该方法具有快捷、污染小、可靠性强的特点,适用于桃胶中多种农药残留的快速定性和定量检测。
