This method is for determining combined nitrogen in liquefiedpetroleum gas (LPG). The method determines all nitrogen compoundsthat are extractable by aqueous acid, including ammonia, amines,nitriles and amides. The method is particularly useful for LPGsamples containing nitrogen species, such as ammonia and amines,which can readily adsorb on stainless steel surfaces in contactwith the LPG. The procedure yields quantitative results in therange of approximately 0.1 mass-ppm to approximately 3 mass-%.