This is a method for determining basic nitrogen compounds inrefinery gases in the region of 0.1 to several hundred parts permillion. It can be used for gases which are largely condensable bydry ice-acetone mixture, such as stabilizer gas and polymerizationunit feed stocks; and also for gases which are low in condensables,such as recycle gas from catalytic reforming units or catalytichydrogen treating units. The procedure will not distinguish betweenammonia and low-boiling amines.