The formaldehyde content of cigarette smoke solutions was determined by using a chromotropic acid method. To 1 ml of cigarette smoke samples and standards (1-7 |xg/ml formaldehyde) in 25-cm glass test tubes, 25 (jlI of 1% chromotropic acid was added and mixed. Six milliliters of concentrated sulfuric acid was then added to each tube. The tubes were cooled to room temperature, and the absorbance was read at 580 nm. Color development was stable up to 3 h. The formaldehyde content of the cigarette smoke samples was determined from the standard curve. ventolin inhalers
Acrolein was assayed with a method employing HgCl2-4-hexylresorcinol. Twenty microliters of 4-hexylresor-cinol reagent (5 g of 4-hexylresorcinol in 5.5 ml ethanol) was added to 1 ml of cigarette smoke samples and standards (1-6 (Jig/ml acrolein) in 10-cm glass tubes. After mixing, 40 jjlI of HgCl2 reagent (3 g of mercuric chloride in 100 ml ethanol) was added and mixed. One milliliter of saturated trichloroacetic acid was added, and the tubes were immersed in a 60°C water bath for 15 min. The tubes were cooled immediately upon removal, and the absorbances were read at 605 nm approximately 15 min after removal from the water bath. Color development was stable up to 2 h. The acrolein content of the cigarette solutions was determined from inspection of the standard curve.