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: invention refers to analytic chemistry, namely, to preparation of indicator compositions for production of indicator tape with subsequent photocolorimetric measurement of formaldehyde content in the air. For this purpose, the following composition of indicator solution is used with this solution containing ingredients in wt.%: glycine - 1.5-12; methyl red - 0.004-0.4; alkali - 0.04-0.6; ethyl alcohol - 30-70; distilled water - the rest. A method for preparation of indicator solution consists in obtaining solution A by dissolution of methyl red in ethyl alcohol and obtaining solution B by dissolution of glycine in distilled water. Then solutions A and B are mixed to obtain crimson-scarlet color, after that alkali is added with mixing for 30-40 min until the color turns yellow.

EFFECT: invention allows to assess formaldehyde content in the air due to selective color reaction using the composition with minimum ingredient number, absence of solution toxicity and its chemical air resistance. Besides that, indicator tape produced using this composition has long shelf-life.

2 cl, 1 tbl, 1 dwg, 3 ex