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锎-252等离子体解吸((252)~Cf Plasma Desorp-tion,简称(252)~Cf PD)质谱,也可称为锎-252裂变碎片诱导解吸((252)~Cf Fission Fragment Indu-ced Desorption,简称(252)~Cf FFID)质谱。一、基本原理当吸附在固体表面上的分子发生热分解时,分解速度由传递能量到不稳定的振动态需要的时间和振动周期决定。如果表面气化的速度大于分解速度,则分解作用对质谱分析的干扰不大。快速加热有利于样品的气化。例如,在160℃进行化学电离分析时,在释放促甲状腺素激素(TRH)的谱图上,热分解产物生成的离子峰(m/z 235)较质子化分子离子峰(m/z363)的强度要高。当把样品迅速加热到215℃(10℃/S)时,两个离子的强度正好相反。在这种情况下,快速加热产生的高温脉冲颇短,减少了分解作用。
锎 -252 Plasma desorption (252) ~ Cf Plasma Desorp- tion, referred to as (252) ~ Cf PD) mass spectrometry, also known as 锎 -252 Fragment Induced Desorption (252) ~ Cf Fission Fragment Induced Desorption , Referred to as (252) ~ Cf FFID) mass spectrometry. First, the basic principle When the molecules adsorbed on the solid surface thermal decomposition occurs, the decomposition rate from the transmission of energy to the unstable vibration state of the time and vibration cycle decision. If the rate of surface gasification is greater than the rate of decomposition, decomposition does not interfere with mass spectrometry. Rapid heating facilitates the gasification of the sample. For example, in the chemical ionization analysis at 160 ° C, the ion peak (m / z 235) produced by the thermal decomposition product is lower than the peak of the protonated molecular ion peak (m / z 363) in the spectrum of thyrotropin releasing hormone (TRH) High intensity. When the sample is rapidly heated to 215 ° C (10 ° C / s), the intensities of the two ions are exactly the opposite. In this case, the high temperature pulse generated by rapid heating is quite short, reducing the decomposition.