| 摘要 |
PURPOSE:To permit the analysis accuracy to be increased by a simple technique, by a method wherein a toluene standard solution is stepwisely sampled and diluted with a color reagent and is then analized to prepare a calibration curve. CONSTITUTION:A toluene standard solution (86.1mug/m ) is stepwisely sampled 0, 0.5, 1.0, 1.5 and 2.0m . Each of the samples is diluted with a color reagent (formalin sulfate solution) so as to be 10ml in volume. After the samples are left to stand for 20min, the absorbancy thereof is measured at 472nm to prepare a calibration curve. Then, the toluene vapor in the ambient air is collected (1l/ min) by means of an impinger. The collecting time is 10min, for example. In this case, as an absorbing solution, 10ml of a 90% ethanol is employed. The toluene is dispensed and diluted with a color reagent formalin sulfate solution) so as to be 10ml in volume. After the diluted toluene is left to stand for 20min, the absorbancy thereof is measured at 472nm, thereby to carry out a quantitative analysis of toluene. |
