Nebulisers direct high efficiency

A further study by the Olesik group [138] used an interface with a laminar flow in the direction of the detector. The interface was a stainless-steel tee with the capillary threaded through the colinear ends of the tee. A sheath electrolyte was delivered through the lower arm of the tee with a peristaltic pump. Both a high efficiency nebuliser (HEN) and a concentric glass nebuliser were used in the study the former was used with a conical spray chamber and the latter with a Scott double-pass spray chamber. Increasing the sheath electrolyte flow-rate enabled the laminar flow to be eliminated, therefore improv-... 

Sensitivity and detection limits of ICP-MS are governed by the absolute amount of analytes introduced to the plasma per time unit. Hence, sample transport efficiency of the ICP-MS introduction system will critically affect detection limits in CE-ICP-MS. A general drawback of CE is that concentration-based detection limits are limited by the small sample injection volumes and the electrophoretic peak width. Interfaces employing nebulisers in combination with spray chambers yield analyte transport efficiencies of < 100%, depending on the nebuliser and solution flow rate. Consequently, the sensitivity of CE-ICP-MS can be improved by using introduction systems with 100% aerosol transport efficiency, such as the direct injection nebuliser and the direct injection high-efficiency nebuliser. ... 

As the vast majority of LC separations are carried out by means of gradient-elution RPLC, solvent-elimination RPLC-FUR interfaces suitable for the elimination of aqueous eluent contents are of considerable use. RPLC-FTTR systems based on TSP, PB and ultrasonic nebulisa-tion can handle relatively high flows of aqueous eluents (0.3-1 ml.min 1) and allow the use of conventional-size LC. However, due to diffuse spray characteristics and poor efficiency of analyte transfer to the substrate, their applicability is limited, with moderate (100 ng) to unfavourable (l-10pg) identification limits (mass injected). Better results (0.5-5 ng injected) are obtained with pneumatic and electrospray nebulisers, especially in combination with ZnSe substrates. Pneumatic LC-FI1R interfaces combine rapid solvent elimination with a relatively narrow spray. This allows deposition of analytes in narrow spots, so that FUR transmission microscopy achieves mass sensitivities in the low- or even sub-ng range. The flow-rates that can be handled directly by these systems are 2-50 pLmin-1, which means that micro- or narrow-bore LC (i.d. 0.2-1 mm) has to be applied. 

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