| 摘要 |
The invention relates to the deprotonation of highly charged fragment ions obtained by electron transfer dissociation of highly charged analyte cations. The invention consists in supplying the radical anions for electron transfer dissociation (ETD) of positively charged analyte ions, as well as the non-radical anions for reducing the charges on the dissociation products by proton transfer reactions (PTR), from the same substance, or the same mix of substances, whereby both types of ions are produced within the same ion source 8. The ratio of the two types of anions supplied is controlled by varying the operating voltages of the ion source, in particular the extraction voltage. The ion source 8 is preferably an electron-attachment negative chemical ionization (NCI) ion source supplied with a hydrogen rich gas such as methane. |
