The Benefit of Interlaboratory Studies

Product testing and compliance have both been a recent topic in the news, particularly in regards to the safety of consumer products in both the pharmaceutical and dietary supplement industries. It has brought to light a question to many consumers: Are these companies even testing what they produce?

In reality, companies in these industries have a variety of choices when it comes to choosing a testing laboratory to send their products. There are options such as full-service labs, specialty labs, local and international labs, or even setting up an internal lab on site.

Chances are that if you’re familiar with product testing, you’re currently happy with the laboratory choice you’ve made. But here’s a thought: How do you know the lab you’re using is providing you with good data?

Try an Interlaboratory Study

The first thing most companies look for when considering another lab is if the lab is “accredited”. Sure, a list of accreditations the lab possesses is impressive, but accreditations don’t necessarily speak to a quality of a lab. They simply tell you that a lab has a system in place that meets some sort of recognized standard.

We suggest to periodically check lab results with another lab, which simply means conducting an interlaboratory study. When comparing two separate lab results head-to-head, you’ll be made aware of any discrepancies that may be occurring in the current analysis.

On the flip side, it can also confirm your results if they are ever questioned by an outside regulatory agency. Regardless of the outcome, this comparison will help your company better understand the beginning-to-end process your choice lab is using to analyze your products.

An interlaboratory study will ultimately give you the confidence and peace of mind that data you are receiving is accurate and correct. This is especially important for those companies that are relying solely on their in-house lab results.

Additional Measures

Some labs have additional quality checks in their operating procedures to ensure that the data that is being produced is as accurate as possible.

One of the options CSL offers is a method validation specific to our clients’ unique sample matrices. While these validations vary by client and product, they all generally include analyzing replicate samples and matrix spikes through our full analytical process at varied amounts and conditions to verify the method’s reproducibility, detection limits, ruggedness, etc.

Other quality checks CSL utilizes:

  • A strict quality assurance program Our procedures and documents are available during on-site audit. These include: sample control documentation, individual analytical methods, analyst training, equipment preventive maintenance, calibration, corrective actions, internal quality control activities, data validation, and data reporting.
  • Matrix spike samples – At CSL, we include at least one matrix spike per ten samples. A matrix spike is created by adding a known amount of the element(s) to be tested directly to the sample. We analyze the sample and the matrix spike independently and assess their ability to recover the added spike from the sample.
  • Proficiency Testing (PT) samples – PT samples are materials which contain target analytes (like lead, cadmium, etc.) which we purchase through regulatory agencies as a part of our accreditation protocols. The amount of each analyte in a PT sample is known only to the provider and is not made available to us. We analyze this type of sample as part of our normal routine, and report the results to the PT provider.
  • Commercially prepared reference materialsStandard Reference Materials (SRMs) are substances which are homogeneous and contain well established analyte amounts. These materials are verified by several laboratories using different analytical techniques so that they can be confidently used to calibrate instruments or assess the accuracy of an analytical method. We use commercially prepared SRMs to help assure the accuracy of our methods, such as instrument calibration.
  • The use of “blanks” – Because our main focus is on heavy metals analysis, we are often quantitating elements in the microgram and nanogram range. At levels this small, we need to ensure no contamination is occurring during the course of sample preparation or analysis. We use method blanks, which are samples that do not contain the element of interest. The blank is treated like a sample in terms of processing, so any contamination which would affect the samples should be evidenced in the analysis of the blank.
  • Interpreting lab results – We say it often, but our customer service is top notch. We’re proud of the fact that our staff is always able and willing to help a client answer any and all question they have regarding lab results. In situations that require more explanation, we realize the importance of our clients understanding the numbers on a report so they are then able to explain it to others.

Choose us as your back up!

Choosing CSL to be an “alternate lab” eliminates the scramble to qualify a new lab whenever disruptions may occur. Our quality, capability, and experience make us your top choice for an alternate lab. Once CSL is qualified for your company, we’ll be ready to assist when instrument failures, disputes, or poor service occur with your current lab of choice.

For testing of heavy metals or minerals in your product, please contact Chemical Solutions either by calling us at (717) 697 –7536 or submitting a request.  Either way, we’ll respond promptly to your inquiry.

Reference: The “Heavy Metal Analysis and Interim Recommended Limits for Botanical Dietary Supplements: White Paper”, published in January 2009 by the American Herbal Products Association.

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