Acetic acid indoors

A. F. L. Godoi, L. van Vaeck, R. vanGrieken, Use of solid phase microextraction for the detection of acetic acid by ion trap gas chromatography mass spectrometry and application to indoor levels in museums, J. Chromatogr. A, 1067, 331 336 (2005). 

Carboxylic acids The smallest carboxylic acid, formic acid, can be measured using infrared spectroscopy (Table 11.2), since it has characteristic absorption bands. As discussed earlier and seen in Fig. 11.33b, mass spectrometry with chemical ionization using SiF5 also revealed HCOOH in an indoor environment (Huey et al., 1998). However, since the sensitivity in these initial studies was about two orders of magnitude less than that for HN03, the detection limit may be about the same as that for FTIR and TDLS. Formic and acetic acids have been monitored continuously from aircraft (Chapman et al., 1995) and their surface flux determined by eddy correlation (Shaw et al., 1998) using atmospheric pressure ionization mass spectrometry. Detection limits are about 30 ppt. 

Figure 15.12 summarizes the ratio of indoor-to-outdoor concentrations of HCHO and higher aldehydes as well as formic and acetic acids measured in some conventional homes. Concentrations of all of these compounds, except possibly propionaldehyde, are significantly higher indoors, suggesting that not only... 

FIGURE 15.12 Ratio of indoor-to-outdoor concentrations of formic and acetic acids and some carbonyl compounds in some homes unshaded, data from Reiss et al., 1995a, for summer data shaded, data from Zhang et al., 1994a. 

Exposure to acetaldehyde may occur in its production, and in the production of acetic acid and various other chemical agents. It is a metabolite of sugars and ethanol in humans and has been detected in plant extracts, tobacco smoke, engine exliaust, ambient and indoor air, and in water. 

Wang (1975) determined indoor air concentrations of several bioeffluents in a mechanically ventilated 2400-m lecture theatre containing 225-389 occupants. These were [with range of average concentrations (pg/m )] ethanol (43-84), acetone (49-70), methanol (37-72), butyric acid (42-54), acetic acid (21-24), phenol (15-18), amyl alcohol (13-27), diethyl ketone (6-20), ethyl acetate (9-31), toluene (7-36), acetaldehyde (2-8) and allyl alcohol (4-9). Many of these were considered to originate from metabolic breakdown of foodstuffs or from food components. 

Nielsen G.D., Hansen L.R, Nex0 B.A., Poulsen O.M. (1998 a) Indoor Air Guideline Levels for Formic, Acetic, Propionic and Butyric Acids. Indoor Air Suppl. 5, 8-24. 

Wood is usually used as a building material and not as a cladding of metallic materials however, sometime wood parts are used in contact with metallic materials, for storage and packaging, and furthermore, metallic components are used as joints for wood parts. Wood contains ceUnlose, hani-cellulose, lignin, and water in equilibrium with atmospheric humidity, and also complex substances such as acetylated polysaccharides. Some of these substances, by hydrolysis, generate acetic acid, and others release formic acid, propionic acid, and butyric acid, all volatile substances that can dramatically affect the behavior of the atmosphere, especially in indoor environments. On one hand, wood contains tannins, which combine with the metals and may give rise to protective corrosion... 

Chamber (Caltech Indoor Chamber Facility) experiments have also been carried out by Lee et al. to monitor the time evolution and yields of gas-phase VOCs produced by the ozonolysis of ten different terpenes [197] six monoterpenes (a-pinene, (3-pinene, 3-carene, terpinolene, a-terpinene and myrcene), two sesquiterpenes (a-humulene and p-caryophyllene) and two oxygenated terpenes (methyl chavicol and linalool). Several gas-phase oxidation products were identified including formaldehyde, acetaldehyde, formic acid, acetone, acetic acid, nopinone and pinonaldehyde. 

The use of ultrasounds to aid the extraction is another possibility. Phthalates (Abb et al. 2009) and perfluorinated alkanoic acid (PEA) (Kato et al. 2009) determinations have been reported. Ethyl acetate (phthalates) or formic acid with methanol (perfluoroalkyl chemicals) was added to the dust sample, and extraction was performed in an ultrasonic bath at room temperature for 10 min. In the case of phthalates an enrichment step was not carried out to avoid the risk of contamination. Pyrethroids and their metabolites can also been extracted from indoor dust samples by adding methylene chloride followed by sonication for 10 min (Starr et al. 2008). Another option is the combination of Soxhlet extraction with an ultrasonic treatment (Schecter et al. 2009). 

The relevant material components in indoor environments can be conveniently segregated into six categories. Corrosive gases include SO2 and NOx (primarily NO and NO2), as well as organic acids such as formic and acetic... 

Analysis of corrosion products on copper, zinc, nickel, and iron specimens that had been exposed to various benign corrosive indoor atmospheres shows large amounts of infrared bands from carboxylate ions such as formate, acetate, and oxalate. This may be an indication of a stronger influence of carboxylic acids and other organic compounds under benign conditions than in more aggressive atmospheres. 

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