Determination of sulfur in coal by solid sampling graphite furnace high-resolution molecular absorption spectrometry

摘要

An analytical procedure for quantitative analysis of sulfur in coal by direct solid sampling graphite furnace highresolution continuumsourcemolecular absorption spectrometry (HR-CS GFMAS) is described,which is based on themolecular absorption of tin sulfide. The heating programis optimized, and a series of chemicalmodifiers (Ir,Mg, Pd, Ru, W, Zr) are tested. All measurements are accomplished with an Ir coated platform and Pd as modifier, because the best results are achieved. Accurate results are obtained using the central SnS line of the band found at 271.578 nm with precision values between 1 and 6%. A limit of detection of 10 ng S absolute is achieved. Furthermore, the trueness of the procedure is verified by analysis of certified referencematerials. Several coal sampleswith a concentration range from0.8 to 21.7 mg g~(-1) S and three certified reference materials are analyzed. In all cases, simple calibration with aqueous standards is found to be possible and the sample throughput is 2-3 samples per hour (6 replicates per sample).