Application of total reflection long capillary cell to determination of fluoride in drinking water

Lei WEI, Kitao FUJIWARA, Keiichiro FUWA
1986 Analytical Sciences  
Colorimetric determination of fluoride ion in drinking water was done with a long capillary cell (LCC) (length: 0.7-4 m). When a solution whose refractive index exceeds that of the cell material (Pyrex=] .474) is put into the capillary, a wave-guide(total reflection) cell is obtained, its transmissibility to source light is independent of cell shape. Color development was based on the la-ALC method: lanthanum-alizarin complexone was added to the sample. The fluoro-lanthanum-alizarin complexone
more » ... lizarin complexone which formed was combined with N,N-diethylaniline and extracted into isoamyl alcohol. Fluoride complex extracted to isoamyl alcohol was mixed with a mixture of carbon disulfide and acetone (the final refractive index of analyte solution=1.57). Extension of cell length longer than 1 m provided highly sensitive colorimetry. Enhancement of absorption was O.5-2.5x103 times in magnitude by using 4 m LCC. Detection limit and recovery of this method were 10 ng/I and 93-104% (for 50 µg/l), respectively. The present method was applied to the determination of fluoride in drinking water collected around Tokyo.
doi:10.2116/analsci.2.213 fatcat:uyqedvcttbbwheerazcies2g3y