摘要：Several conventional methods for spectrophotometric determination of pyridine in stack gases were examined, but they did not show a satisfying result and a new method has been established. The gas containing pyridine was absorbed in 0.1 N sulfuric acid and reacted with pyrazolone and cyanogen chloride to form a blue complex. The absorbance was measured at near 620 nm. The calibration curve followed Beer's low. Ammonia and nitrogen dioxide did not interfere but sulfur dioxide interfered the determination, which was removed by potassium hydroxide trap without loss of pyridine. The color was stable at least for 60 min and the procedure is comparatively simple.
