Improved thermospray accurate mass measurement using a magnetic sector instrument

Abstract

A method permitting accurate mass measurement of full-scan thermospray mass spectra is presented. Improved resolution and sensitivity were achieved by the addition of source cryopumping. Ion beam stability was enhanced by adaptation of a vaporizer tip with a sapphire orifice. Large systematic errors, such as previously reported with currentcontrolled scanning and widely spaced reference ions, were greatly reduced by employing field-controlled magnetic scanning. The method permits measurements accurate to better than 10 ppm whie employing a simple polyethylene glycol standard.