MASS SPECTROMETER APPARATUS

摘要

A method for the calibration of atmospheric pressure ionisation analytical apparatus including means for ionising a gaseous test sample comprises supplying to the ionising means a mixture of ionizable calibration compounds in solid form, the compounds having respective ionized species of known different molecular weights. The ionisation may be chemical ionisation, the apparatus including means for heating the test sample, the calibration compounds being volatile in the heating means. The invention includes a mixture of ionizable calibration compounds in solid form for use in calibration of desorption analytical apparatus, the compounds being volatile and having respective species when ionized of known different molecular weights.