| 摘要 |
A diagnostic composition for determining the hydrogen ion concentration of biological fluids comprises an indicator or combination of indicators which exhibit a colour change upon being subjected to a change in hydrogen ion concentration, an alkali metal carrageenate, e.g. the sodium salt thereof, polyvinyl pyrrolidone and a polyalkylene glycol, e.g. polypropylene or polybutylene but preferably polyethylene glycol. A preferred indicator composition consists of 1 part Methyl Red and 20 parts Bromthymol Blue. The diagnostic composition may be impregnated on a bibulous carrier, e.g. paper, by dissolving the ingredients in aqueous alcohol and drying the bibulous material in an oven at 80-150 DEG C. for 5-10 mins. A wetting agent may be used in making the solution. A preferred diagnostic composition comprises Methyl Red, Bromthymol Blue, refined carrageen extract, polyvinyl pyrrolidone and polyethylene glycol, (m.w. 4,500), impregnated on a bibulous carrier. |
