A STUDY ON THE ABNORMAL COPPER CONTENT IN LACCAIC ACID (LAC DYE)

The copper content in stick lac has not been reported. The copper content in stick lac as determined by atomic absorption spcctlophotometry was 9.49 ppm. The copper content in coarse seed lac, fine seed lac, powder lac, and corpses of the lac insect, these four flassified components of stick lac were 8.06 ppm, 13.44 ppm, 16.38 ppm, 49,66 ppm respectively by the same method.The copper in stick lac existed mainly in the corpses of the lac insect and that was the main pollution source causing copper pollution in laccaic acid (lac dye ) . The fact that copper pollution of laccaic acid in stick lac could not be avoided was concluded after considering its biological source and chemical nature.