Su X L, Yu B S, Tan H W, Yang X R, Nie L H, Yao S Z
New Material Research Institute, Chemistry and Chemical Engineering College of Hunan University, Changsha, People's Republic of China.
J Pharm Biomed Anal. 1998 Jan;16(5):759-69. doi: 10.1016/s0731-7085(97)00108-8.
A novel flow-injection (FIA) system, for the rapid and direct determination of both total ammonia (T[NH3]) and total carbon dioxide (T[CO2]) in clinical blood samples, has been developed. Samples were injected into a carrier stream of H2O, then emerged with a reagent stream, where the analyte was converted into a gaseous species and diffused across a PTFE gas-permeable membrane into an acceptor stream. The trapped NH3/CO2 in the acceptor was determined on line by a bulk acoustic wave (BAW) impedance sensor. At a through-put of 20 and 65 h(-1), the proposed system exhibited a linear frequency response up to 200 micromol l(-1) ammonium and 20 mmol l(-1) bicarbonate with a detection limit of 1.0 and 10 micromol l(-1), respectively. Results obtained for T(NH3) in serum and T(CO2) in plasma were in agreement with those obtained by the conventional glutamate dehydrogenase (GDH) method and gas-sensing electrode method, respectively. The effects of composition of acceptor stream, cell constant of conductivity electrode, sample volume, flow rate and potential interferents on the FIA signals were also discussed.
已开发出一种新型流动注射（FIA）系统，用于快速直接测定临床血液样本中的总氨（T[NH₃]）和总二氧化碳（T[CO₂]）。将样本注入H₂O载流中，然后与试剂流一起流出，在试剂流中分析物转化为气态物质，并通过聚四氟乙烯透气膜扩散到接受流中。接受流中捕获的NH₃/CO₂由体声波（BAW）阻抗传感器在线测定。在20和65 h⁻¹的通量下，该系统对高达200 μmol l⁻¹铵和20 mmol l⁻¹碳酸氢盐呈现线性频率响应，检测限分别为1.0和10 μmol l⁻¹。血清中T(NH₃)和血浆中T(CO₂)的测定结果分别与传统谷氨酸脱氢酶（GDH）法和气体传感电极法的结果一致。还讨论了接受流组成、电导电极的电池常数、样本体积、流速和潜在干扰物对FIA信号的影响。
