Characteristics of potassium ion-doped glass slab optical waveguide as an absorption cell and its application to the spectrophotometric detection of Methylene Blue
✍ Scribed by Kin-ichi Tsunoda; Hiromitsu Itabashi; Hideo Akaiwa
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 590 KB
- Volume
- 276
- Category
- Article
- ISSN
- 0003-2670
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✦ Synopsis
The characteristics of a K+-doped glass slab optical waveguide (SOWG) as an absorption cell are discussed in terms of effective path length (L,) and relative sensitivity (S/cm). The longest L, value of 11 pm was observed with TM, mode of the SOWG with a 30-mitt ion-exchange process in molten KNO,, which was in good agreement with the calculated value of 9.7 pm. The K+-doped SOWG provides higher sensitivity by one to two orders of magnitude than conventional absorption measurements of an analyte on a glass surface to which perpendicular irradiation of source light on the surface is applied. Octadecylsilane modification of the SOWG surface was effective for the sensitive detection of Methylene Blue by flow analysis where an ion pair of Methylene Blue and lauryl sulphate was formed.