仪器分析课件-第九章紫外吸收光谱分析Ultraviolet.ppt

1、 NV transitions include *transitions in saturated organic compounds and*transitions in unsaturated compounds.NQ transitions:a kind of transitions arise from the electron excitation from nonbonding orbital to anti-bonding orbital.NR transition:electron is excited to a higher level until it is ionized

2、 to molecular ion.Charge transfer transitions:charge(electron)transfers between different parts of the compound due to charge redistribution of the compound excited by a radiation.Mn+Lb-M(n+1)+L(b-1)-hFe3+SCN-2+Fe2+SCN2+hd-溶剂影响吸收波长，吸收强度及精细结构（fine structure）钨灯或卤钨灯钨灯或卤钨灯可见光源可见光源 3501000nm氢灯或氘灯氢灯或氘灯紫外光

3、源紫外光源 200360nm1光源：光源：2吸收池：吸收池：玻璃玻璃能吸收能吸收UV光，仅适用于可见光区光，仅适用于可见光区 石英石英不能吸收紫外光，适用于紫外和不能吸收紫外光，适用于紫外和 可见光区可见光区 要求：匹配性（对光的吸收和反射应一致）要求：匹配性（对光的吸收和反射应一致）3 3单色器：包括狭缝、准直镜、色散元件单色器：包括狭缝、准直镜、色散元件 棱镜棱镜对不同波长的光折射率不同对不同波长的光折射率不同色散元件色散元件 分出光波长不等距分出光波长不等距 光栅光栅衍射和干涉衍射和干涉 分出光波长等距分出光波长等距4 4检测器：将光信号转变为电信号的装置检测器：将光信号转变为电信号的装

4、置光电池光电池光电管（红敏和蓝敏）光电管（红敏和蓝敏）光电倍增管光电倍增管二极管阵列检测器二极管阵列检测器类型：类型：仍然分为单光束型和双光束型两种仍然分为单光束型和双光束型两种min%11maxmax，shcmE%06.01002101.1%/101.1100/101.1143505.0334%11肾上腺酮mlmgmlglEACcmCLAmol 定量依据：步骤：步骤：babababaAEEAEE22221111；和测定；和测定bbaababaCECEAAA11111bbaababaCECEAAA22222bababbabbaaEEEEEAEAC12211221babaabaababEEEEEAEAC12212112步骤：步骤：babababaAAAAAA222111babbaabababaAAAAAAAAA )()(212121aaAAa2121和的等吸收点选bbbbbbbbaCECEEAAA )(2121bbabbbabEAEEAC21toda透达