Abstract
A direct injection high efficiency nebulizer (DIHEN) was modified for µLC-ICP-MS by inserting an additional internal capillary with od 90 µm and id 20 µm to minimize the interface dead volume. The modified DIHEN was compared with a conventional microflow nebulizer with a spray chamber interface with respect to sensitivity, signal stability and organic modifier dependency at flow rates ranging from 0.5 to 5 µl min−1. Although the modified DIHEN was slightly less sensitive, its signal stability was superior, its modifier dependency was less pronounced and its chromatographic resolution was much better due to its extremely small dead volume. These characteristics were demonstrated by the analysis of a mixture of synthetic phosphopeptides (31P detection) and synthetic