Apex desolvating system

Protocol 1 is not instrument specific, but will assume the use of a Thermo Fisher magnetic sector instrument, preferably with an Aridus or Apex desolvating introduction system. In Protocol 1, elution of uranium from TRU SPE columns is accomplished with 5% v/v (1.4 M) HF. 

If an Aridus desolvating system is used, then sweep gas and nitrogen addition gas should be optimized for the Aridus system. The optimal values depend entirely on the unit, the conditioning of the membrane, and so on. If either an Aridus or Apex is... 

Operation under dry plasma conditions is the second option. The standard solution is introduced as a dry aerosol through a desolvating system (such as an Aridus, DSN-100 or Apex unit) [12, 23]. The use of this configuration significantly reduces oxide-based interferences. This is essential for some elements, such as sulfur [19]. 

Microflow nebulizer with heated spray chamber and Peltier-cooled condenser An example of this design is the Apex inlet system from ESI. This unit includes a microflow nebulizer, heated cyclonic spray chamber (up to 140°C), and a Peltier multipass condenser/cooler (down to -5°C). A number of different spray chamber and nebulizer options and materials are available, depending on the application requirements. Also, the system is available with Teflon or Nafion microporous membrane desolvation, depending on the types of samples being analyzed. Figure 17.12 shows a schematic of the Apex sample inlet system with the ctoss-Aow nebulizer. 

If a desolvating introduction system such as a Cetac Aridus, Elemental Scientific Apex-HF, or equivalent is used, this should be optimized respectively to less than 1% CeO+ formation. In these cases, CeO" is used as a representative measure of polyatomic interference formation. 

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