Abstract: In order to investigate elemental analysis in non-conducting samples by direct current glow discharge mass spectrometry (dc-GDMS), a method for detecting impurities in α-Al₂O₃ powder was established. Copper powder acted as a kind of conducting host matrix, which was fully mixed with α-Al₂O₃ powder，and then pressed the mixture into wafers. Effect of glow discharge conditions, such as discharge current, discharge gas flow, ion source temperature, and pressure conditions, such as mixture ratio, pressure, etc. on discharge stability and sensitivity were investigated. The experiment condition was optimized. Total signal of Al, O and Cu normalization was adopted, and the impurities contents in α-Al₂O₃ powder were calculated in subtraction. The method precision is within 54% and the detection limits are between 0.005 μg/g and 0.57 μg/g. The results coincide with that of direct current spark atomic emission spectrometry.