Büldt A, Lindahl R, Levin J O, Karst U
Westfälische Wilhelms-Universität Münster, Anorganisch-Chemisches Institut, Abteilung Analytische Chemie, Wilhelm-Klemm-Str. 8, 48149 Münster, Germany.
J Environ Monit. 1999 Feb;1(1):39-43. doi: 10.1039/a807631f.
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.
一种利用空气中甲醛扩散采样的新方法已被开发出来。甲醛通过使用浸渍有N-甲基-4-肼基-7-硝基苯并呋喃（MNBDH）和磷酸的玻璃纤维过滤器进行采样。形成的甲醛腙用乙腈从过滤器上解吸下来，并通过高效液相色谱（HPLC）在474nm处进行紫外/可见检测来测定。在48次实验中，采样速率被确定为24.7 mL min-1，相对标准偏差为7%。测得的采样速率不依赖于甲醛浓度（0.1 - 1.0 mg m-3）、采样时间（15 - 482分钟）或相对湿度（20 - 85%）。对于15分钟的采样周期，检测限为70微克 m-3，对于8小时的采样周期，检测限为2微克 m-3。
