An analytical procedure for the determination of metal nd non-metal impurities at ppm level in crude silicon and purified trichlorosilane has been developed. The analyses of most metal impurities are carried out with direct atomic absorption spectrophotometric techniques. A fluoremetric method is developed for the assay of aluminum. Boron and phosphorus are determined via the methylene blue method and the molybdophosphoric acid method, respectively. Our analytical data clearly indicates that the chlorination process of our design is highly effective in removing impurities in the course of chemical purification of silicon.