Sampling and Determination of Formaldehyde Using Solid-Phase Microextraction with On-Fiber Derivatization
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- 作者：Perry A. Martos and Janusz Pawliszyn
- 刊名：Analytical Chemistry
- 出版年：1998
- 出版时间：June 1, 1998
- 年：1998
- 卷：70
- 期：11
- 页码：2311 - 2320
- 全文大小：107K
- 年卷期：v.70,no.11(June 1, 1998)
- ISSN：1520-6882
文摘
Gaseous formaldehyde is sampled by derivatization witho-(2,3,4,5,6-pentafluorobenzyl)hydroxylaminehydrochloride (PFBHA) adsorbed onto poly (dimethylsiloxane)/divinylbenzene solid-phase microextraction fibers. Theproduct of the reaction is an oxime which is thermallyverystable and insensitive to light. The oxime can beanalyzedby gas chromatography with flame ionization detection andother detectors. Loading PFBHA on the fiber is byroom-temperature headspace extraction from aqueous solutionsof PFBHA. The process of loading and desorption ofunreacted PFBHA, and oxime formed, is both highlyreproducible and reversible, with more than 200 loading,sampling, and analysis steps possible with one fiber.Thestandard formaldehyde gas concentrations studied rangedfrom 15 to 3200 ppbv with sampling times from 10 s to12 min. Quantification can be achieved viainterpolationfrom calibration curves of area counts as a function offormaldehyde concentration for a fixed sampling time.Sampling for 10 s yields a method detection limit of40ppbv and at 300 s the method detection limit is 4.6 ppbv.This is equal to or better than all other conventionalgrabsampling methods for gaseous formaldehyde employingsampling trains or passive sampling techniques. Alternatively, gaseous formaldehyde can be quantified with anempirically established apparent first-order rate constant(0.0030 ng/(ppbv s) at 25 
C) for the reaction betweensorbed PFBHA and gaseous formaldehyde. This first-order rate constant allows for quantitative analyses without a calibration curve, only requiring detectorcalibrationwith the oxime. This new method was used for theheadspace sampling of air known to contain formaldehyde, as well as other carbonyl compounds, and fromvarious matrixes such as cosmetics and building products.
C) for the reaction betweensorbed PFBHA and gaseous formaldehyde. This first-order rate constant allows for quantitative analyses without a calibration curve, only requiring detectorcalibrationwith the oxime. This new method was used for theheadspace sampling of air known to contain formaldehyde, as well as other carbonyl compounds, and fromvarious matrixes such as cosmetics and building products.