Determn. of formaldehyde concn. in aq. media - using pH sensor carrying microorganisms which oxidise formaldehyde to acid, in rapid, simple and inexpensive process without using added reagents

摘要

The concn. of HCHO in an aq. medium is determined by: (1) immobilising an HCHO-utilising microorganism, able to generate a pH change in the medium, on the pH-sensitive surface of a sensor, the organism being positioned between the surface and a water-insoluble membrane permeable to HCHO and pH-changing products; (2) contacting the sensor with a known amt. of aq. solns. of known HCHO concn. and buffer capacity 10 micromole-10 mmole/l, and detecting the resulting change in pH (as measurement signal) over a specified length of time; (3) contacting the sensor with a similar soln. of unknown HCHO content and repeating the measurement; and then (4) determn. of HCHO content by comparing results of steps (2) and (3). Also new is an appts. contg. the modified sensor. Pref. the microorganism is Pseudomonas putida J3 strain. USE/ADVANTAGE - This method is simple, rapid, inexpensive, reliable, specific and selective, and can be used in microbiology, chemistry, medicine, environmental protection and various industries. It does not require expensive or toxic reagents (e.g. exogenous co-enzymes) and can be applied to analysis of HCHO in air (once this has been brought into soln.).