1.1. History
Formaldehyde was described in the year 1855 by the Russian scientist Alexander Michailowitsch Butlerow. The technical synthesis by dehydration of methanol was achieved in 1867 by the German chemist August Wilhelm von Hofmann. The versatility that makes it suitable for use in various industrial applications was soon discovered, and the compound was one of the first to be indexed by Chemical Abstracts Service (CAS). In 1944, Walker published the first edition of his classic work Formaldehyde.(1) Between 1900 and 1930, formaldehyde-based resins became important adhesives for wood and wood composites. The first commercial particle board was produced during World War II in Bremen, Germany. Since 1950, particle board has become an attractive alternative to solid wood for the manufacturing of furniture. Particle board and other wood-based panels were subsequently also used for the construction of housing. Adverse health effects from exposure to formaldehyde in prefabricated houses, especially irritation of the eyes and upper airways, were first reported in the mid-1960s. Formaldehyde emissions from particle boards bonded with urea formaldehyde resin were soon identified as the cause of the complaints. As a consequence, a guideline value of 0.1 ppm was proposed in 1977 by the former German Federal Agency of Health to limit human exposure in dwellings. Criteria for the limitation and regulation of formaldehyde emissions from wood-based materials were established in 1981 in Germany and Denmark. The first regulations followed in the United States in 1985 or thereabouts. In Germany and the United States, large-scale test chambers were used for the evaluation of emissions. Although the chamber method is very reliable, it is also time-consuming and expensive. This meant there was a strong demand for simple laboratory test methods.(2)

Formaldehyde in the Indoor Environment

A colorimetric method for estimating serum triglycerides

Eight different forms of cytochrome P-450 (P-450) were purified to electrophoretic homogeneity by a common procedure from liver microsomes of rats treated with phenobarbital or beta-naphthoflavone. Antibodies were prepared to seven of these forms in rabbits. The eight P-450s were distinguished by spectral properties of the ferric, ferrous, and ferrous carbonyl forms, apparent monomeric molecular weights, peptide mapping, immunological reactivity as discerned by double-diffusion immunoprecipitin analysis and crossed immunoelectrophoresis, and catalytic activities toward the substrates acetanilide, aminopyrine, aniline, benzo[a]-pyrene, d-benzphetamine, N,N-dimethylnitrosamine, 7-ethoxycoumarin, 7-ethoxyresorufin, ethylmorphine, p-nitroanisole, testosterone, and (R)- and (S)-warfarin. Crossed sodium dodecyl sulfate-polyacrylamide gel immunoelectrophoresis was used to estimate the levels of each of the eight forms of P-450 present in the liver microsomes of untreated rats and rats treated with phenobarbital, 5,6-benzoflavone, pregnenolone-16 alpha-carbonitrile, isosafrole, or the polychlorinated biphenyl mixture Aroclor 1254. In each situation, the sum of the levels of these eight P-450s was at least as high as the spectrally determined P-450 content. The results clearly demonstrate that individual forms of P-450 can be induced by different compounds and that a single compound can lower the level of one form of P-450 while inducing one or more other forms of P-450. Catalytic activities toward each of the substrates observed with microsomal preparations are compared to rates predicted on the basis of the content of each of the eight P-450s. These studies provide a basis for further studies on the regulation of individual P-450s, the physical properties of the different P-450s, and the metabolic consequences of changes in the forms of P-450 in rat liver models.

Purification and characterization of liver microsomal cytochromes p-450: electrophoretic, spectral, catalytic, and immunochemical properties and inducibility of eight isozymes isolated from rats treated with phenobarbital or beta-naphthoflavone.

Chelating and free radical scavenging mechanisms of inhibitory action of rutin and quercetin in lipid peroxidation.

Iron-catalyzed hydroxyl radical formation. Stringent requirement for free iron coordination site.

Bonnichsen, R. K. (1947). Arch. Biochem. 12, 83. Dalgliesh, C. E. (1951). Quart. Rev. chem. Soc., Lond., 5,227. Daigliesh, C. E. (1952). Biochem. J. 52, 3. Eckert, H. W. (1943). J. biol. Chem. 148, 205. Elliott, K. A. C. (1932a). Biochem. J. 26, 10. Elliott, K. A. C. (1932b). Biochem. J. 26, 1281. Galston, A. W. (1949). Plant Phy8iol. 24, 577. Gordon, S. A. & Nieva, F. S. (1949). Arch. Biochem. 20,356. Gustafson, F. G. (1949). Science, 110, 279. Happold, F. C. (1950). Advanc. Enzymol. 10, 51. Henderson, J. M. & Bonner, J. (1952). Amer. J. Bot. 39, 444. Horn, M. J. & Jones, D. B. (1945). J. biol. Chem. 157, 153. Keilin, D. & Hartree, E. F. (1951). Biochem. J. 49, 88. Kenten, R. H. & Mann, P. J. G. (1952). Biochem. J. 50,360. Knox, W. E. (1951). Brit. J. exp. Path. 32, 462. Knox, W. E. & Mehler, A. H. (1950). J. biol. Chem. 187,419. Makino, K., Satoh, K., Fujiki, T. & Kawaguchi, K. (1952). Nature, Lond., 170, 977. Morton, R. K. (1950). Nature, Lond., 166, 1092. Nason, A. (1950). Amer. J. Bot. 37, 612. Proctor, B. E. & Bhatia, D. S. (1953). Biochem. J. 53, 1. Reichstein, T. (1932). Helv. chim. acta, 15, 1110. Singer, T. P. & Kearney, E. B. (1950). Arch. Biochem. 29, 190. Sizer, I. W. (1947). Fed. Proc. 6, 202. Stanier, R. Y. & Tsuchida, M. (1949). J. Bact. 58, 45. Tang, Y. W. & Bonner, J. (1947). Arch. Biochem. 13, 11. Teas, H. J. & Anderson, E. G. (1951). Proc. nat. Acad. Sci., Wash., 37, 645. Weil, L., Gordon, N. G. & Buchert, A. R. (1951). Arch. Biochem. 33, 90. Wildman, S. G., Ferm, M. G. & Bonner, J. (1947). Arch. Biochem. 13, 131. Wildman, S. G. & Muir, R. M. (1949). Plant Physiol. 24, 84.

T. Nash

Papers

The colorimetric estimation of formaldehyde by means of the Hantzsch reaction