Determination of Memory-Prone Elements Using Direct Injection High Efficiency Nebulizer Inductively Coupled Plasma Mass Spectrometry

A direct injection high efficiency nebulizer (DIHEN) and a large-bore DIHEN (LB-DIHEN) are investigated for the determination of difficult-to-analyze and memory-prone elements (mercury, iodine, and boron). The determination of such elements is problematic using conventional sample introduction systems incorporating spray chambers and/or desolvation devices owing to their large surface area and hence long wash-out characteristics. With the DIHEN or LB-DIHEN, the spray chamber is eliminated and the dead volume is reduced to <10 μL, thus reducing memory effects. In comparison with the crossflow-spray chamber combination, wash-in and wash-out times are reduced to less than 10 s when a DIHEN or LB-DIHEN is used for mercury, iodine, and boron at a concentration of 100 ng/mL. The accuracy of the DIHEN-ICPMS (inductively coupled plasma mass spectrometry) technique is evaluated in the analysis of the National Institute of Standards and Technology standard reference material (NIST SRM) 2670 (Toxic Metals in Freeze-Dried Urine) and NIST SRM 8414 (Bovine Muscle Powder). Further, the effectiveness of the DIHEN-ICPMS technique is examined in the determination of mercury and iodine in an alternative remedy medicine (seahorse genital tonic pills) and boron in rodent liver samples as part of a pharmacokinetic screening study for boron neutron capture therapy.