A direct injection high efficiency nebulizer interface for microbore high-performance liquid chromatography-inductively coupled plasma mass spectrometry

A simple, relatively low-cost interface is investigated for high-performanc e liquid chromatography using inductively coupled plasma mass spectrometry (ICP-MS) detection. The interface consists of a one-piece micronebulizer (d irect injection high efficiency nebulizer, DIHEN), positioned in the ICP to rch for the direct nebulization of solution into the base of the argon plas ma. Microcolumn separations were performed in two modes: one. reverse-phase separation of three naturally occurring cobalamin species (hydroxocobalami n, cyanocobalamin, and adenosylcobalamin); and two, ion-pairing reverse-pha se separation of five organolead and organomercury species [triethyllead (E t3Pb+), triphenyllead (Ph3Pb+), methylmercury (MeHg+), ethylmercury (EtHg+) and phenylmercury (PhHg+)]. For a 10 muL injection, absolute sensitivity i n the ion pairing mode ranged from 2430 counts pg(-1) (EtHg+) to 35880 coun ts pg(-1) (Ph3Pb+) and peak area reproducibility (%RSD, n=5) ranged from 0. 7% (EtHg+) to 5.1%., (PhHg+). Absolute detection limits were in the low- to sub-picogram range. Importantly, no plasma instability or carbon depositio n on the nebulizer tip was observed using organic modifiers in the mobile p hase of up to 20%.