Chromatographic determination of harmful compounds emitted during hardening of phenol-formaldehyde resins

The optimum conditions for determination of methanol, phenol, o-cresol, m-, p-cresols and formaldehyde, from one sample air, in the mixtures emitted during the hardening of phenol-formaldehyde resins were elaborated. In order to isolate the tested compounds from air a four layer adsorbing tube was used - 300 mg and 50 mg of silica gel and 100 mg and 50 mg of silica gel covered with 2,4-dinitrophenylhydrazine. The desorption coefficients of methanol, phenol, o-cresol, m-and p-cresols from silica gel by 5% ethanol solution in acetonitrile were: 81.4%, 97.0%, 98.3% and 97.9%, respectively. The the recovery coefficient of formaldehyde was 97.0%. The analytical procedure enables to determine methanol within 10-200 mg m(-3), phenol 1-20 mg m(-3), o-cresol 0.2-4 mg m(-3), m- and p-cresols - 0.2-4 mg m(-3) and formaldehyde - 0.04-1.2 mg m(-3) in the workplace air in the presence of other substances a which may occur during the process of hardening phenol-formaldehyde resins.