INDICATOR SOLUTION FOR PRODUCTION OF INDICATOR TAPE FOR PHOTOCOLORIMETRIC MEASUREMENTS OF FORMALDEHYDE CONTENT AND METHOD FOR PREPARATION THEREOF Russian patent published in 2017 - IPC G01N31/22 

FIELD: chemistry.

SUBSTANCE: for the production of indicator tapes for photocolorimetric measurements in the determination of gaseous ammonia in air, a solution containing an indicator (bromocresol green), an indicator solvent (alcohol) and a stabilizing additive (potassium bisulfate (KHSO₄) solution in distilled water) is prepared at the following component ratio, wt %: Bromocresol green 0.05-0.2; Potassium bisulfate (KHSO₄) 0.7-1.2; Ethyl alcohol 18-25; distilled water the rest. The specified ingredients used to manufacture packing paper registering the indicator to change the yellow coloring on the green when interacting with ammonia during the 2-3 min. After 10 min, the indicator tape spontaneously returns the original yellow colour.

EFFECT: invention provides the use of chemically resistant, non-toxic solution with selective colour response to gaseous ammonia in the air for manufacturing indicator tapes.

2 cl, 1 tbl, 1 dwg, 3 ex