固態光度偵測器應用在流動注入式分析法中測定硝酸根離子之研究

A Solid-State Photometric Detector for Determination of Nitrate by Flow Injection Analysis

吳麗娟(Lih-Jiuan Wu) ； 眭台生(Tai-Sung Hsi)

《化學》 48卷4期 (1990/12) Pp. 281-290

https://doi.org/10.6623/chem.1990036

摘要

以綠色發光二極體(LED)當作光源及光二極體(photodiode)當作偵測器，自製一組流動式固態光度偵測器，並將其應用在流動注入式分析(FIA)系統中，定量測定水中硝酸根含量。硝酸根離子的測定，首先是將水樣通過鎘金屬還原管柱，使其中的硝酸根離子(NO_3^-)還原成亞硝酸根離子(NO_2^-)，然後再與N-1-naphthylethylenediamine dihydrochloride和sulphanilamide進行顯色反應。對2ppm之硝酸根標準容易連續測定36次，所測得結果之相對標準差(r.s.d.)在1%以下；校正曲線支線性範圍為0.05~5ppm NO_3^--N，而偵測極限為0.02ppm NO_3^--N。將測定5種不同水樣中硝酸根含量的結果，分別與離子層析法及FIA配合傳統之UV-Vis偵測法所測得之結果相比較，發現結果相當一致，顯示將固態光度偵測器應用在FIA系統上是可行的。

並列摘要

A flow injection manifold in conjunction with a home-made flow-through solid-state photometer, which incorporates a green light-emitting diode (LED) as the radiation source and a photodiode as the detector, is described for the determination of nitrate in water samples. Nitrate is first reduced to nitrite through a copperized-cadmium column, followed by the color-forming reaction with N-1- naphthylethylenediamine dihydrochloride and sulphanilamide. The relative standard deviation for 36 replicate injections of 2 ppm NO_3^--N standard solution is better than 1%. The linear dynamic range is 0.05~5 ppm NO_3^--N. and the detection limit is 0.02 ppm NO_3^--N. By comparison with the results of ion chromatography and traditional UV-Vis spectrophotometric detector, the good agreement among the results on the determination of nitrate in 5 water samples, demonstrates the feasibility and effectiveness of the solid-state photometric detector for flow injection analysis (FIA).