The Investigation of a 13-mm Torch for Use in Inductively Coupled Plasma-Mass Spectrometry

A 13-mm torch is evaluated for use in inductively coupled plasma-mass spectrometry (ICP-MS). With this system, an analytically useful plasma can be supported at 1.35 kW applied rf power and 9.35 L/min total argon flow. The effect of operating parameters (nebulizer flow rate, rf power, sampling depth, and ion-lens voltages) on analyte ion signals was examined, also. The optimal nebulizer-gas flow rate, sampling depth, and power for the 13-mm torch were found to be comparable to those used for the standard (18-mm) torch. Similar trends were seen between the two systems when these parameters were varied. Under optimal operating conditions, the 13-mm torch was found to produce comparable sensitivities, oxide-ion ratios, and doubly charged ion ratios. The most significant difference exhibited between the two torches was the independence of the doubly charged ion ratio on plasma parameter settings for the 13-mm torch.