Water Quality Recommendations for ICP-OES Samples

Answer

This Information Applies To: Agilent 5000 series ICP-OES Systems (5100/5110/5800/5900)

Issue

Discussion of Water Quality for use in the make up of Samples, Blanks, and Standards for ICP-OES

Resolution 

Summary of Recommendations for Water Quality in samples, standards, and blanks for ICP-OES system applications:

• Low ionic content / resistivity 18 MΩ•cm  
• Low particle content / particles sizes < 0.2 µm
• Low organic content / Total organic carbon (TOC)
• Low bacteria content 

   

Description of recommendations for Water Quality in ICP-OES applications

• Type I ultrapure water is a good option in most cases
  
  • Type I ultrapure water is specified in ASTM D1193
    • Resistivity of > 18 MΩ-cm at 25 °C / Conductivity of < 0.056 µS/cm 
    • Total organic carbon (TOC)  < 50 ppb
    • Sodium < 1 ppb
    • Chloride < 1 ppb
    • Total Silica < 3 ppb
  • ASTM standards are further subdivided into A, B, and C to describe microbiological contamination
  • This is, as always, subject to individual method samples and requirements. 
• For ICP-OES applications, it is important to minimize the amount of particles
  • It is recommended to use a 0.45 µm filter for filtering samples before running
  • Some types of organic content could stick to the nebulizer and have negative impact on the aerosol
  • Some regulations might require that TOC stays below specific limits
  • Bacteria in samples can behave similar to particles

Tips: See Checking for a Blocked ICP-OES Nebulizer

Tips: See Cleaning a Blocked Nebulizer in the Agilent ICP-OES System, Cleaning the 5000 Series ICP-OES Torch, Organic Matrices and Cleaning the 5000 Series ICP-OES Torch, Acid and Aqueous Matrices for ICP-OES system cleaning recommendations