TECHNIQUE AND INDICATOR FOR DETECTION OF LEAD, PROCESS OF MANUFACTURE OF INDICATOR Russian patent published in 2003 - IPC

FIELD: analytical chemistry, manufacture of indication means. SUBSTANCE: technique detecting lead includes operation of bringing of tested object in contact with indicator plate. Aqueous solution of 4-(2- pyridylazo)resorcin in concentration of 0.08-0.20 per cent by mass with aqueous solution of ammonium acetate in concentration of 20.0-40.0 per cent by mass is utilized in the capacity of indicator composition. Indicator is made of indicator plate comprising carrier with high capillary properties with indicator composition applied to it. Plate is placed in wetted state into sealed package. Package comes in the form of pack one side of which is double-layer side. Inner layer is clear and has central indicator hole. Process of manufacture of indicator includes impregnation of carrier plate with indicator composition. Carrier plate is put into pack made of water and gas impermeable material with hole in one side of pack. Impregnation is carried out with the aid of dropping method through central hole, then package is sealed by covering this side of pack with hole with second layer of water and gas impermeable material. EFFECT: simplified and reliable technique, expanded application field of technique. 5 cl, 2 dwg, 1 tbl