Analytical Standards

 

Chromatographic Specialties has access to a wide variety of analytical standards and high-purity reference materials. 

Our current offering includes many of the premier manufacturers of analytical reference materials in the world.
Additionally, some of our chromatography and sample preparation suppliers have niche offerings of reference product.

These include:

 

Our offering continues to grow as we solidify our place as THE source of analytical reference materials in Canada.  We have developed this section on our website that we will continue to update to showcase the breadth of our offering and offer technical tips and materials of interest to anyone using these types of product; we suggest you use it as a resource for keeping you informed of new developments.

Need an analytical standard – make us your first call!  Chances are we are able to provide both primary and secondary sources of the material you require; if not, we can lead you to where you can find it. 
 

Chromatographic Specialties' Analytical Standards Material

Supplier Reference Standards FAQ pages:

Our Suppliers' Accreditations:


 

TECHNICAL TIPS AND ADVICE

The Importance of CAS Numbers When Requesting Standards

Going through a long list of compounds for an analytical standard and adding a CAS number for every compound on the list is something nobody wishes to do. Unfortunately, it's become crucial for accurate processing of ever lengthening analyte lists, especially for international methods. Many drugs and pesticides have local variations on name or spelling while CAS numbers are constant throughout the world. CAS numbers are now the primary identifier for analytes in most, if not all, ISO 17034 Certified Reference Materials.

To let us help you find the best solutions for extensive analyte lists please:

  • Include CAS numbers whenever you have them.
  • Include a technical contact to clarify any oddities in a list when submitting a quote request.
  • Let us know if you need us to add the CAS numbers for you. Otherwise we'll need to check if you have or can get them.
  • If you need us to add CAS numbers, understand it will take us time to do so, and that you'll need to review and approve the CAS numbers and associated chemical names before you order.

The following 2 sites are places where CAS numbers can be found:

Contact our Technical Team for further assistance.

 


 

Tips for Ordering Standards

  • Not all analytes are soluble in all solvents.  You do not need to know which solvents work best with which analytes but be aware that manufactures may be able to provide better solvent options.
  • In some products a co-solvent maybe necessary.
  • If shelf life is important being locked into a solvent might not be the best choice, allowing the manufacture to choose the best solvent can lead to a longer shelf life product.  Some solvents can even cause degradation of the analytes as an example, Acrolein breaks down in Methanol, and results in an exceptionally short shelf life standard.
  • Not all solvents have infinite solubility for all analytes, leave the options open for a lower concentration for a better product.
  • Not all analytes are compatible with each other.  For example, Nitrate & Nitrite cannot be in the same standard as they will react with each other, causing degradation.  Allowing the manufacture to choose which analytes play well together, can result in a longer shelf life and better product.
  • When asking for Inorganic standards know your Counter Ion.

 

A Guide to Concentration Units:

 

    Percent   

    Parts per Million (ppm)   

    Parts per Billion (ppb)       Parts per Trillion (ppt)   
   Weight-Volume         % w:v             µg/mL, mg/L         pg/µL, ng/mL, µg/L              pg/mL, ng/L
   Weight-Weight      % w:w                   µg/g    

We do not accept Molar concentration values.
To convert to concentration weight-volume ppm, use the formula: CµgmL=CmolesLxMw(gmole)x1000

 


 

The Importance of Ordering Long Standards Lists as Sub-Mixes

  • The probability of having a chemical incompatibility in a standard is proportional to 1-pn2, with p being the probability of successfully combining any pair of analytes and n being the number of analytes in the mix. Put more simply, the chance of having a chemical incompatibility in a standard gets very near certainty very quickly as the number of components grows.
  • Splitting large standards into sub-sets both increases p (since we're grouping similar compounds together) and decreases n, so it's much easier to provide a stable standard by splitting into 2 or 3 subsets.

  

Note: The actual formula is more complex, approaches 1-pn2 for large values of n. Graph is based on the actual formula.
Math afficionados may contact tech@chromspec.com for more details.