Ion focusing system

Fig. 5.3 Overview of commercial instrument, lA-Lab (model L-250G-IA, manufactured by Canon Anelva, Kanagawa, JAPAN). This equipment consists of direct inlet probe (DIP), Li+ attachment reaction chamber with LP emitter in it, the ion focusing system, and the quadrupole mass spectrometer. Li+ is supplied by a Li+ emitter. There are two types of interface for sample introduction an introduction tube for gases and a direct inlet probe for solids and liquids. ( 2009, Canon Anelva, Data sheet)...

It is of the utmost importance to clean the mass analyzer at regular intervals using a mixture of organic solvent, acid, and water in order to remove residues from the heated capillary. Additionally, the ion focusing system has to be cleaned with an alcohol, because deposits in this system result in a decrease in sensitivity and resolution. 

FIGURE 6.2 An ion-focusing system that uses a hollowed-out ion mirror to deflect the ion beam 90° to the mass analyzer, while allowing photons, neutrals, and solid particles to pass through (courtesy of Varian Inc.). 

There are a number of ways to compensate for space charge matrix suppression in ICP-MS. IS has been used, but unfortunately does not address the fundamental cause of the problem. The most common approach used to alleviate or at least reduce space charge effects is to apply voltages to individual lens components of the ion optics. This is achieved in a number of different ways, but irrespective of the design of the ion-focusing system, its main function is to reduce matrix-based suppression... 

However, the design of the ion-focusing system or the number of lens components used is not as important as its ability to handle real-world matrices. Most lens systems can operate in a simple aqueous sample because there are relatively few matrix ions to suppress the analyte ions. The test of the ion optics comes when samples with a real matrix are encountered. When a large number of matrix ions are present in the system, they can physically knock the analyte ions out of the ion beam. This shows... 

---