| 摘要 |
A chemical test-paper comprises an absorbent paper impregnated with one or more re-agents sealed between two synthetic resin foils or between one synthetic resin foil and a resin coated paper, at least one edge of the absorbent paper being free of synthetic resin. The foils may be of any water-insoluble synthetic resin such as polyvinyl chloride, polyterephthalic acid esters, polyethylene coated polyterephthalic acid esters, polypropylene and polyamides and the foils may be perforated. The paper is sealed in the foils by heat, e.g. by heated rollers or by high frequency welding. Multi-test papers may be made by sealing several spaced strips, impregnated with different reagents, between the foils and coloured strips for comparative purposes may also be incorporated. The examples describe (1) a test paper for detecting glucose comprising filter paper impregnated with a solution of o-toluidine, peroxidase, glucose oxidase, tartrazine and fatty acid polyethylene glycol ester in aqueous alcohol; (2) a multi-test strip comprising (a) a strip as in (1), (b) a strip impregnated with an aqueous alcoholic solution of citric acid, trisodium citrate, dioctyl sodium sulphosuccinate and tetrabromo-phenolphthalein for testing protein, and (c) a strip impregnated with methanolic bromothymol blue, phenolphthalein and methyl red for pH determination; and (3) a test strip for testing nitrites comprising (a) a strip of filter paper impregnated with a -naphthyl ammonium oxalate (containing 1 % 2:6-di-t-butyl-4-methylphenol), sulphanilamide and oxalic acid in acetone/methanol medium and comparative colour strips impregnated respectively with (b) methanolic tetraiodofluorescein sodium salt, 1-aminobenzene-4-sulphonic acid-2-hydroxynaphthalene-6-sulphonic acid sodium salt and (c) methanolic tetraiodofluorescein sodium salt only. Specifications 867,192, 888,039 and German Specifications 909,504 and 1,094,017 are referred to. |
