Aridus desolvating system

Urine QCs (see below), standards, samples, and ultrapure water blanks are acidified with ultrapure nitric add. The volume of urine depends on the concentration range and instrument setup. For a magnetic sector instrument with an Aridus desolvation system and nitrogen addition, 2-4 mL of urine is the typical volume required for samples with uranium concentrations as low as 0.003 pg/L. For samples with uranium concentrations <10 ng/L, 4mL of urine is preferred. Four milliliters of addified urine is the maximum volume that will also fit in the Eichrom 0.21 g TRU resin SPE columns without the additional funnel. Three hundred seventy-five microliters of concentrated nitric acid per milliliter of urine is added to each unknown urine, QC sample, or water blank before introduction onto the column. 

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... 

Ting, B. G., Pappas, R. S., and Paschal, D. C. 2003. Rapid analysis for plutonium-239 in urine by magnetic sector inductively coupled plasma-mass spectrometry using Aridus desolvation introduction system. J Anal Atom Spectrom 18(7), 795-797. 

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]. 

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 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. 

Microflow nebulizer coupled with membrane desolvation An example of this is the Aridus system from Cetac Technologies. The aerosol from the nebulizer is either self-aspirated or pumped into a heated PEA spray chamber (up to 110°C) to maintain the sample in a vapor phase. The sample vapor then enters a heated PTFE membrane desolvation unit, where a coun-... 

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