连续光源原子吸收光谱法测定分子吸收研究

连续光源原子吸收光谱法由于是使用高功率的高压短弧脉冲氙灯,其辐射波长为覆盖190~850nm范围的连续光源,且加之以高分辨率分光系统和可视化固态检测器,可对光谱测量中的分子吸收进行测定。该方法可以用于原子吸收光谱法(AAS)中的空气/乙炔火焰的背景吸收,也可以用于测定一些在火焰中可形成分子的元素的测定。同时,还可以用于测定其他的分子吸收及相关的研究。本研究主要应用连续光源的原子吸收光谱测定空气/乙炔火焰中的分子背景吸收。通过将普通的AAS燃烧头加以简单的改进,利用燃烧头水平/垂直光路的两次测定,能有效的测定空气/乙炔火焰中所形成的分子在不同波长条件下的分子吸收情况。

铜合金中高含量锌的火焰原子吸收快速测定法

选用锌的次灵敏线307 6nm,以空气 乙炔火焰原子吸收法测定铜合金中高含量锌,确定了仪器的最佳工作条件,试验了各种酸及酸度、共存离子及基体对锌的影响,以此拟定了简便、准确和快速的测定方法。样品实测的回收率为95 6%～104 4%,相对标准偏差为0 51%～0 99%。

Effect of Replacement of Headspace Gas on N_2O and CO_2Emissions in Anaerobic Incubation of Soil

To study effect of C2H2 and change of headspace gas on N2O emission, denitrification, as well as CO2emission, slumes of an agricultural soil were anaerobically incubated for 7 da3’s at 25 ℃. Both N2O reduction and CO2 emissions were inhibited by the addition of 100 mL L-1 of C2H2. However, the inhibition to CO2 emission was alleviated by the replacement of headspace gas, and the N2O emission was enhanced by the replacement. Acetylene disappeared evidently from the soil slumes during the incubation. Consequently results obtained from the traditional C2H2 blocking technique for determination of denitrification rate, especially in a long-time incubation, should be explained with care because of its side effect existing in the incubation environments without change of headspace gas. To reduce the possible side effect on the processes other than denitrification, it is suggested that headspace gas should be replaced several times during a long-time incubation.