The Top 5 Problems with Reference Materials (& How to Fix Them)

Have you ever received a product in the mail that wasn't what you thought it was going to be?  Perhaps the fit wasn't right or it didn't work as you expected?  No matter where you order from or what you order, you've probably encountered this problem once or twice.  

Well reference materials are no different.   

At ASI we try to be the very best for our customers and create the highest quality products.  But when our humanity kicks in, here are the top 5 problems that customers encounter and how we they can be solved. 

  1. My analysis is not matching the certified value on the. bottle or COA.
  2. There is a concentration listed when I asked for zero.
  3. I'm not seeing the element I am looking for.
  4. The documentation doesn't match the label on the standards.
  5. This isn't what I ordered.


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1. The concentration is not listed on the COA and/or label. 


Why did this happen?    

  • Product is past expiration date
  • Concentration on the COA/label is listed incorrectly 
  • Labels within the set were mistakenly switched during packaging 
  • The analysis instrument malfunctioned or is out of calibration 
  • Matrix of the standard is not close enough to the matrix of the calibration 
  • The concentration units of the standard to not match the concentration units of the calibration
  • Either incorrect or too many corrections have been made to the analysis
  • Uncertainty of the analysis method is wider than the uncertainty of the COA
  • Element of interest fell out of a complex solution 
  • Element of interest is being masked by something else in the sample
  • Usage or storage instructions on the COA have not been followed
  • It was manufactured incorrectly 

The fix:

  1. Be sure to fully understand the capabilities and limitations of your instrumentation and analytical methods. 
  2. Read the Certificate of Analysis carefully and follow the directions. These are some great examples: 
    1. Vigorously shaking the standard prior to sampling for analysis 
    2. Refrigerating the standard while not in use 
  3. Pay attention to the units of concentration and be careful when using PPM. While most use PPM to represent weight/weight concentrations like mg/kg, PPM can also be used to represent weight/volume concentrations like mg/L. If you are not analyzing water, you will need to know the density of the material being tested in order to properly compare weight/weight to weight/volume. 
  4. Be consistent with sample preparation and testing procedures. Changing things like cups, film, environmental factors, testing times, etc. can wreak havoc on expected analysis results. Be as consistent as possible. 


2. There is a concentration listed when I asked for zero.   


Why did this happen?   

  • We like to use the term blank instead of zero whenever dealing with trace levels to avoid confusion.
  • It is unlikely, almost impossible, to find a true blank material with zero of anything in it.   

The fix:   

  • We will let you know what concentration to expect in your blank.


    Sulfur Impurity in Blank 

    Mineral Oil 

    ~10-100 ng/g (PPB) 

    Diesel Fuel 

    ~15-100 ng/g (PPB) 


    ~0.5-1.0 ug/g (PPM) 

    Crude Oil 

    ~400-500 ug/g (PPM) 

    Residual Oil 

    ~2000-2500 ug/g (PPM) 

    We have two versions of the COA to manage this situation 
    • Total Sulfur (or other element of interest)
    • Blank Correction (or Method of Addition)
  • Measuring the blank yourself and applying a blank correction is also an option. Just let us know when you are placing your order and we will be happy to make the standards accordingly.


3. I’m not seeing the element I am looking for.


 Why did this happen?

  • It was not put in the standard 
  • When working with XRF, it is common for elements to interfere or "mask" each other during analysis.

The fix: 

  • When analyzing multiple elements at the same time via XRF, be sure to calibrate with standards that have the concentrations of each element randomized unlike the wear metal dilution series standards you may be used to. This will help account for any interferences you may expect or not expect.
  • With more complex formulations, be sure to shake vigorously prior to sampling for analysis to ensure a good mix. If you see sedimentation at the bottom after shaking, something is coming out of solution and you should give us a call. 


4. Documentation doesn’t match the label on the standard.   

  • Specifications, such as those below, are all typed in many times in various places. They are the most-commonly misrepresented pieces of data. 
    • Lot number  
    • Expiration Date 
    • Concentration 
    • Concentration Units 

The fix:   

  • Each piece of data entry represents an opportunity for the most humanly of mistakes…the typo. While we continually improve our processes to remove data entry wherever possible, the ability to customize most of what we do requires manual data entry in many places. If you find a discrepancy on the label or documentation, please call us so we can fix it right away.

5. This isn't what I ordered.   

  • With great customization comes great responsibility
  • We do our best to accommodate every customization request that comes our way so we depend heavily on receiving accurate specifications  

The fix: 

  • When making a quote or order request, make sure to understand your part number, any product codes, descriptions, or other specifications related to the products you are requesting so that we know exactly what to make for you. 
  • When in doubt, you can provide us with information such as previous lot number, analytical instrument being used, or ASTM method being followed. 


Each of these problems we work tirelessly to prevent from happening again.  Some of these problems are small and some of them large.  However, no matter the size there is always a solution and we are here to help you with it and fix it for you.    


Have you encountered any of these problems with your reference standards order?  Were they fixed to your satisfaction?  


Share your experiences with us by emailing us at  We would love to hear from you! 


As always, thank you for taking the time to read and visit us here at our home on the web.  You mean the world to us! 


Cheers To Your Quality,



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