DIAGNOSTIC AGENTS FOR THE DETECTION OF UROBILINOGEN MATERIALS IN BODY FLUIDS

1,208,980. Detection of urobilinogen bodies. BOEHRINGER MANNHEIM G.m.b.H. 24 Oct., 1968 [26 Oct., 1967; 3 July, 1968], No. 50552/68. Heading BIX. A diagnostic agent for the detection of urobilinogen bodies in body fluids comprises at least one strong (defined) solid or liquid acid and at least one compound which undergoes a colour change with urobilinogen bodies and has general formula in which R 1 and R 2 which may be the same or different are hydrogen or halogen atoms or sulphonic acid (-SO 3 H), cyano, nitroso, carbbalkoxy, carbamide, hydroxyl, acyloxy, alkoxy or open-chain or cyclic, saturated or unsaturated secondary or tertiary amino radicals provided that R 1 and R 2 are not both hydrogen atoms, or R 2 is a secondary straight chain or branched, open chain or mono- or polycyclic alkyl or aralkyl radical, R 1 then having the same meaning as above, or in which R 1 and R 2 together are an oxygen or sulphur atom or a sulphonyl, alkylthionium, imino, alkylimino, unsubstituted or substituted arylimino radical or a dialkyleneimino, alkyleneimino or oxaalkyleneimino radical, R 3 is hydrogen or alkyl and n and m which are the same or different are 0, 1, 2 or 3. The strong acid may be sulphosalicylic acid, p-toluene sulphonic acid, potassium bisulphate, glutamic acid hydrochloride, oxalic acid, o-phosphoric acid, hydrochloric acid, maleic acid. The diagnostic agent may be in the form of an absorbent carrier, preferably filter paper impregnated with a solution containing 0.001% to 1% of the colour-change compound and at least 3% of a solid strong acid, and optionally an inert additive such as polyvinyl alcohol, polyvinyl pyrrolidone, copolymers of polyvinyl pyrrolidone, polyvinylacetate, polyglycols; a film of for example polyvinyl butyracetal-polyethylene glycol containing the colour change compound and a solid strong acid, and coated on to PVC foil; or a solution containing the colour change compound and a solid or liquid strong acid. It is stated that compounds of the formula given when dissolved in 2% to 20% hydrochloric acid can be used for detecting indole.