Using glow discharge to directly sputter and ionize solid samples eliminates the need for complicated wet digestion processes. With a double-focusing sector field design, it can achieve nearly full elemental coverage for direct quantitative analysis of trace impurities in both conductive and some non-conductive materials. Its extremely low matrix effects and full-spectrum scanning capability make it the go-to technique for characterizing and deeply analyzing bulk impurities in high-purity metals, semiconductors, nuclear materials, and battery materials.