目的探究液相色谱―串联质谱仪(liquid chromatography-tandem mass spectrometer,LC-MS/MS)检测饲料中克伦普罗时,环天冬氨酰苯丙氨酸对试验干扰的原因,在此基础上探究出应用LC-MS/MS分析的确证技术与方法。方法应用四极杆―轨道阱高...目的探究液相色谱―串联质谱仪(liquid chromatography-tandem mass spectrometer,LC-MS/MS)检测饲料中克伦普罗时,环天冬氨酰苯丙氨酸对试验干扰的原因,在此基础上探究出应用LC-MS/MS分析的确证技术与方法。方法应用四极杆―轨道阱高分辨质谱仪和LC-MS/MS对环天冬氨酰苯丙氨酸、克伦普罗对照品以及含有环天冬氨酰苯丙氨酸的饲料样品进行分析。结果饲料中含有环天冬氨酰苯丙氨酸对克伦普罗的检测干扰的原因为二者母离子及2个子离子的质荷比很接近,且二者离子丰度比也很接近。应用LC-MS/MS分析的确证技术与方法为梯度碎裂离子片段依次匹配比较法。结论应用LC-MS/MS检测会遇到假阳性的问题,这是串联质谱结构与方法原理决定的;建议调整克伦普罗的2个子离子为263.07>168.04,263.07>132.06;用LC-MS的梯度碎裂离子片段依次匹配比较法准确、实用。展开更多
目的分析饲料中铬检测方法存在的问题、原因,并对检测方法进行改进。方法用10 mL 6 mol/L的盐酸溶液处理灰化后的样品,所得样液用原子吸收火焰法进行测定,并与国标法中用20%的硝酸溶液处理灰化后的样品的测定结果进行比较。结果按照国...目的分析饲料中铬检测方法存在的问题、原因,并对检测方法进行改进。方法用10 mL 6 mol/L的盐酸溶液处理灰化后的样品,所得样液用原子吸收火焰法进行测定,并与国标法中用20%的硝酸溶液处理灰化后的样品的测定结果进行比较。结果按照国家标准方法,饲料中铬检测检测结果明显低于用10mL6mol/L的盐酸溶液进行前处理的改进方法,原因是饲料中铬检测标准的前处理过程未能充分解离、提取饲料样品中的铬,而经改进后的方法,使用6 mol/L的盐酸溶液并增加酸溶液用量,可以充分溶解提取样品中的铬。结论 2种方法测定结果差异明显,改进后的方法测定结果更准确。展开更多
The dynamic properties of proton conductivity along hydrogen-bonded molecular systems, for example, ice crystal, with structure disorder or damping and finite temperatures exposed in an externally applied electric-fie...The dynamic properties of proton conductivity along hydrogen-bonded molecular systems, for example, ice crystal, with structure disorder or damping and finite temperatures exposed in an externally applied electric-field have been numerically studied by Runge-Kutta way in our soliton model. The results obtained show that the proton-soliton is very robust against the structure disorder including the fluctuation of the force constant and disorder in the sequence of masses and thermal perturbation and damping of medium, the velocity of its conductivity increases with increasing of the externally applied electric-field and decreasing of the damping coefficient of medium, but the proton-soliton disperses for quite great fluctuation of the ＂force constant and damping coefficient. In the numerical simulation we find that the proton-soliton in our model is thermally stable in a large region of temperature of T ≤ 273 K under influences of damping and externally applied electric-field in ice crvstal. This shows that our model is available and appropriate to ice.展开更多
文摘目的探究液相色谱―串联质谱仪(liquid chromatography-tandem mass spectrometer,LC-MS/MS)检测饲料中克伦普罗时,环天冬氨酰苯丙氨酸对试验干扰的原因,在此基础上探究出应用LC-MS/MS分析的确证技术与方法。方法应用四极杆―轨道阱高分辨质谱仪和LC-MS/MS对环天冬氨酰苯丙氨酸、克伦普罗对照品以及含有环天冬氨酰苯丙氨酸的饲料样品进行分析。结果饲料中含有环天冬氨酰苯丙氨酸对克伦普罗的检测干扰的原因为二者母离子及2个子离子的质荷比很接近,且二者离子丰度比也很接近。应用LC-MS/MS分析的确证技术与方法为梯度碎裂离子片段依次匹配比较法。结论应用LC-MS/MS检测会遇到假阳性的问题,这是串联质谱结构与方法原理决定的;建议调整克伦普罗的2个子离子为263.07>168.04,263.07>132.06;用LC-MS的梯度碎裂离子片段依次匹配比较法准确、实用。
基金The project supported by National Natural Science Foundation of China under Grant No. 90306015
文摘The dynamic properties of proton conductivity along hydrogen-bonded molecular systems, for example, ice crystal, with structure disorder or damping and finite temperatures exposed in an externally applied electric-field have been numerically studied by Runge-Kutta way in our soliton model. The results obtained show that the proton-soliton is very robust against the structure disorder including the fluctuation of the force constant and disorder in the sequence of masses and thermal perturbation and damping of medium, the velocity of its conductivity increases with increasing of the externally applied electric-field and decreasing of the damping coefficient of medium, but the proton-soliton disperses for quite great fluctuation of the ＂force constant and damping coefficient. In the numerical simulation we find that the proton-soliton in our model is thermally stable in a large region of temperature of T ≤ 273 K under influences of damping and externally applied electric-field in ice crvstal. This shows that our model is available and appropriate to ice.
