title: A diffusive sampling device for the determination of formaldehyde in air using N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) as reagent.
abstract: A new method utilizing the diffusive sampling of formaldehyde in air has been developed. Formaldehyde is sampled with the use of a glass fiber filter impregnated with N-methyl-4-hydrazino-7-nitrobenzofurazan (MNBDH) and phosphoric acid. The formaldehyde hydrazone formed is desorbed from the filter with acetonitrile and determined by high-performance liquid chromatography (HPLC) with UV/visible detection at 474 nm. The sampling rate was determined to be 24.7 mL min-1 with a relative standard deviation of 7% for 48 experiments. The measured sampling rates were not dependent on the formaldehyde concentration (0.1-1.0 mg m-3), sampling time (15-482 min) or relative humidity (20-85%). The detection limit was 70 micrograms m-3 for a 15 min sampling period and 2 micrograms m-3 for an 8 h sampling period.
authors.affiliation: Westfälische Wilhelms-Universität Münster, Anorganisch-Chemisches Institut, Abteilung Analytische Chemie, Wilhelm-Klemm-Str. 8, 48149 Münster, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Büldt
authors.forename: R
authors.initials: R
authors.lastname: Lindahl
authors.forename: J O
authors.initials: JO
authors.lastname: Levin
authors.forename: U
authors.initials: U
authors.lastname: Karst
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D004058:Diffusion; D004202:Disinfectants / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D005557:Formaldehyde / Q000032:analysis*; D006834:Hydrazines / Q000737:chemistry*; D007202:Indicators and Reagents / Q000737:chemistry*; D010069:Oxadiazoles / Q000737:chemistry*; D012680:Sensitivity and Specificity
chemical_list: D004202:Disinfectants; D006834:Hydrazines; D007202:Indicators and Reagents; C121458:N-methyl-4-hydrazino-7-nitrobenzofurazan; D010069:Oxadiazoles; D005557:Formaldehyde