Abstract:Compare the Se solution to tea digestion solution，there was obvious matrix effects in the tea digestion solution.As known the collided cell technology（CCT）is a commendable method for eliminating this matrix effect.In this article we used Rh as an internal standard，based the optimized isotope of selenium for test，the flow of CCT gas（7%H2+93%He）was optimized either.The results were that under the flow of gas 5.0 mL/min，determination of isotope78Se as total selenium in the national reference substances of tea，spinach and rice，the recoveries of selenium were between 91%and 98%，the accuracy were met the demands.