Certified Reference Standards (CRS Tubes)

CRS tubes are recommended in many key standard methods (e.g. US EPA Method TO-17) for auditing purposes and as a means of establishing analytical quality control. 

Markes International CRS tubes are certified traceable to primary standards, have a minimum 6 month shelf life and are available with concentrations varying from 100 ng to 1 µg per component.  Each pack of CRS tubes includes a shipping blank to demonstrate the integrity of the storage and transportation process.  Chromatograms from this shipping blank, and an example analysis of a CRS tube are supplied along with the CRS Certificate. 
CRS tubes are available loaded with:

• Benzene, toluene and xylene at levels of 100 ng or 1 µg per component .
• TO-17 standard: benzene, toluene, xylene, dichloromethane, 1,1,1-trichloroethane, 1,2,4-trimethylbenzene, methyl-t-butyl ether, butanol, ethyl acetate, methylethyl ketone).

Custom CRS tubes are also available for a wide range of compounds, contact Markes International directly (enquiries@markes.com) for further information. 

For part numbers and pricing please contact your local Markes distributor

Relevant technical support publications from Markes International can be automatically downloaded from this web site (registration required). Examples include:

• Brochure - Certified reference standards
• TDTS 30 – Certified reference materials for analysis of VOCs in air by thermal desorption
  

Other sorbent tubes and accessories available from Markes include:

• Sorbent tubes
• Sorbents
• Certified Reference Standards
• Sorbent tube accessories
• Diffusive sampling accessories
• TubeTAG