Application of Spray-Type Atmospheric Pressure Glow Plasma Reactor: Ashing of Organic Compounds II

When plasma treatment is carried out in the after glow region of an electrical discharge, the decay rate and the density of the active species are very important factors for the treatment efficiency. They are known to depend on the linear gas flow rate (gas velocity) and on the residence time of the treatment gas in the discharge zone, respectively. In our previous study, we found that the spray-type atmospheric pressure glow plasma reactor with O₂/He or O₂/Ar mixture treatment gases had a satisfactory ashing rate of a solid organic compound (OFPR-800; a photoresist). However, the relationships between the gas velocity or the residence time and the ashing rate had not yet been examined. The present study showed clearly that the gas velocity influenced only the transit time, that is the time which the gas mixture took to progress from the slit nozzle to the sample surface, but it did not influence the generation of the active species. On the other hand, the generation rate of active species in the discharge zone was found to be strongly dependent on the residence time. The ashing rate was found to increase with increasing the residence time up to about 30 ms, beyond which it saturated. From optical emission spectroscopy measurements, the maximum ashing rate could be correlated with the emission intensities corresponding to He 3p³P-2s³S (388.8 nm) and O 3d⁵D-3p⁵P (926.5 nm) bands. These results are of practical interest.     

比浊法测定氯化石蜡中氯量

以Na2CO3-MgO-KOH为灰化固定剂,用灰化法处理氯化石蜡样品。对测定条件、灰化条件及AgCl胶体的稳定性进行了考察。建立了比浊法测定氯化石蜡中氯的新方法。线性范围为0~5μg/mL。测定结果的相对标准偏差≤0.6%,加标回收率为97.5%~102.3%。     

灰化法磷测定中不同灰化助剂的效果比较

以磷酸二氢钠和磷酸氢二钠与脱氧腺苷三磷酸（dATP)的混合溶液为磷标样,比较了MgSO4,Mg(NO3)2和MgCl2等灰化助剂的作用效果。结果发现,磷标样中加入MgSO4经500℃灼烧后用0.2mol/L HCl于80℃浸提残渣0.5h不能使磷全部回收;而MgCl2、Mg(NO3)2、MgAc2、CaCl2等助剂,却都能使灼烧后的磷完全回收。在采用MgSO4高温灰化法分析海水中的颗粒磷和总磷或有机体中的磷时,应当用MgCl2作为灰化助剂取代MgSO4。尽管Mg(NO3)2也是高效的灰化辅助剂,但其应用的危险性有较多的手工操作限制了它的广泛应用。