AOAC 2018

Held in August, the 2018 AOAC International Meeting in Toronto, Canada was an excellent opportunity for Pickering Laboratories to be closer to our customers in Canada and the northern United States. The annual AOAC meeting brings experts in food safety, food integrity and public health together to develop and validate analytical methods. This year, Canadian Governmental Laboratories were in significant attendance as well.

Mike Gottschalk and Maria Ofitserova met with existing customers and other attendees interested in our instrumentation and consumables. We exhibited the latest in post-column applications at our booth and sponsored a Vendor Session on our most recently developed method.  We also answered questions our growing Pickering Test Solutions product line. The artificial body fluids we manufacture for research and consumer product testing generated a surprising amount of interest from attending laboratories needing standardized solutions for testing various products.

At our Vendor Session, Maria Ofitserova presented our newly developed and validated method: “Amino Acids Analysis in Dietary Ingredients and Supplements by High-Performance Liquid Chromatography and Post-Column Derivatization.” This method follows the requirements specified by the AOAC Stakeholder Panel on Dietary Supplements and the presentation generated many interesting discussions with representatives of contract laboratories running amino acids analysis.

Maria Ofitserova also continued her work as part of the AOAC Stakeholder Panels and Expert Review Panels. Stakeholders meetings focused on the needs of consumers and industry leaders in the areas of food analysis, supplements analysis and baby formula analysis.

The Pickering Laboratories PINNACLE PCX post-column derivatization instrument is well known for analysis of Amino Acids, Mycotoxins, Glyphosate and many other analytes. Our chemists’ hard work fits very comfortably within the mission of AOAC to research, develop and validate analytical methods.

Visit for our latest post-column applications and product releases.

New Application Notes


State regulations have established maximum allowed levels for Mycotoxins in Cannabis-containing products sold to consumers at the following maximum levels: levels for total Aflatoxins G1, G2, B1 and B2 are set at < 20 ppb and levels for Ochratoxin A at < 20 ppb. Pickering Laboratories developed an easy and sensitive method to analyze Aflatoxins B1, B2, G1, G2 and Ochratoxin A in cannabis plants and edible products. Mycotoxins are isolated using immunoaffinity clean-up columns and analyzed with fluorescence detection. To increase sensitivity of Aflatoxins B1 and G1, an in-line photochemical reactor is installed before the detector. This method utilizes standard HPLC equipment and allows testing laboratories to easily determine Mycotoxins at levels below the limits established by state regulations.

Click to download  Analysis of Mycotoxins in Cannabis Plants and Cannabis Containing Products (MA241).


Analysis of amino acids using cation-exchange columns and Ninhydrin post-column reagent is well-establish methodology that is recommended by the European Pharmacopeia. Pickering Laboratories developed and validated a post-column method for amino acids analysis of dietary supplements that is sensitive, selective and can be used without modifications to analyze capsules, tablets, drinks and other samples. Accelerated methods are available for samples with a limited number of amino acids. 

Click to download  Analysis of Amino Acids in Dietary Ingredients and Supplements (MA397)

Glyphosate in the News

As you may have noticed, Pickering Laboratories has been periodically updating our newsletter subscribers on Glyphosate-related reports in the news.   We are interested in the evolving current events related to Glyphosate regulation and the new research being conducted worldwide. 

Here’s the latest:

Glyphosate residue-free inquires surge as ‘Clean Food’ movement gathers pace.
Glyphosate is being food in consumer products and consumers are finding that a choice is possible.

Common weed killer linked to bee deaths.
A study has found that Glyphosate is a factor in bee deaths and determined the mechanism of effect.

Previous Articles on Glyphosate
Pickering Laboratories offers a post-column method for Glyphosate analysis that has been the industry standard for many years. Our methodology is simpler and more sensitive than LCMS, not to mention less expensive. Please contact us to speak with a chemist about post-column instrumentation or for tips and tricks to improved sample preparation, lower detection limits, or if you’ve got a new sample matrix in mind.

Reagent and Gas Line Clips

Dear valued customer,

You may have noticed that the stiff tubing of the reagent line will sometimes unscrew itself from the white adapter and cap. This will usually end up in a big mess. We have found that securing the gas line and reagent lines together will secure the reagent line and prevent it from unscrewing on its own. We will be launching the Reagent and Gas Line Clips on Oct 8, 2018. Any Vector or Pinnacle manufactured on or after this date will include the new clips. The gas and reagent line clips will also be included with all reagent caps. You can also order packs of two with the ordering information below:

1452-0356       Reagent & Gas Line Clips, pack of 2

Please contact Pickering Support with any questions.

David Mazawa
Technical Support Chemist

Sodium Amino Acid Standard with Norleucine

Dear valued customer,

A new amino acid standard is available for your convenience. This expanded comprehensive set of amino acids with internal standard, Norleucine, can be used for oxidized or non-oxidized samples.

Please see the components listed below.

1700-0165  Sodium Amino Acid Standard with Norleucine, 0.25µmole/mL, pack (5x1mL)

L-Aspartic acid 
Cysteic acid
L-Glutamic acid  
Concentrations µM/mL


Please contact Pickering Support with any questions.

David Mazawa
Technical Support Chemist

Chromatography Quiz #30

Chromatography Quiz #29: Amino Acids Elevated Baseline – RESULTS

Pickering Labs would like to congratulate all of our winners for our previous newsletter’s Elevated Baseline Amino Acids Chromatogram: Tom Schneider from Suffolk County Water Authority, Narjes Ghafoori from LA County Environmental Toxicology Lab, and Dr. David Green from Pepperdine University!

Winners will soon receive: A Harvest Bundle of Gifts from!

This bountiful harvest bundle includes: creamy Pumpkin Cheesecake, a beautiful Autumn Garden Party plant gift, and a Pumpkin-Shaped Gift Basket which features juicy pears, pumpkin bars, cranberry relish, and much more. It’s the perfect way to celebrate the changing of the seasons. Best of all, bundle gift items are sent individually to make the celebration last a little longer!

Congratulations to our quiz winners and we hope they look forward to receiving their gifts next week!

Thank you all for your submissions!

The correct answers for the Elevated Baseline Amino Acids Chromatogram are as follows:

The shift on the baseline is called an ammonia plateau and it is due to the presence of low-level amines and ammonia in the buffers. These compounds accumulate on the column during equilibration time and come out during the gradient in a form of a plateau. Since the buffers have low pH, these compounds are unavoidable but care should be taken to avoid excessive contamination that can cause the plateau to be too high. Amines are present even in the air and get dissolved in buffers as time goes by.

The issue usually comes from buffer A. Try and replace with a new lot if possible.

Below are some tips on how to minimize any potential problems:

  • Remove all filters from the ends of HPLC lines that go into the buffer bottles. All our products are filtered before bottling and these in-line filters only drag contamination from one bottle to another.
  • Replace open buffers on the instrument at least every two weeks. If you don’t use the full bottle in 2 weeks, pour half of the bottle into a clean glass bottle to put on the instrument and tightly cap the remaining portion to keep until future use.
  • Don’t flush column with water, use only Column Regenerant for cleaning the column.
  • Don’t use the first injection of the sequence for calculations since it usually has a different profile due to differences in equilibration time.
  • Program the needle wash between the runs to avoid carry over.
  • If you see unexpected peaks on your blank or other chromatograms make a fresh vial of the solution and run again to confirm the problem. Also run “No Injection” to see if the peaks are coming from the injected sample of from the baseline.
  • Flush HPLC periodically with 100% water, then 100 % methanol, then 100 % water with no column attached (!!!) to keep the lines clean.

Chromatography Quiz #30 – Aflatoxins Analysis, Decreased Signal:

Simply email your answer as well as your full contact information to Rebecca at by December 21, 2018 in order to win. You will receive email confirmation that your submission has been received. The answer to the quiz and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission).

Aflatoxin analysis by photochemical derivatization is achieved with the parameters listed below:

Analytical Column: Mycotox Column, C18 4.6x250mm
HPLC Eluent: Sodium Phosphate buffer PN 1700-1108/Methanol/Acetonitrile (57/28/15)
Flow Rate: 1 ml/min
FLD: Excitation 365nm, Emission 430nm
UVE Photochemical reactor with 254nm UV light: 1.0ml knitted reaction coil.


What could contribute to a decrease in signal?







Biopharmaceuticals and Amino Acids Analysis

By Maria Ofitserova

Biopharmaceuticals are large molecules produced by or extracted from biological sources. They are used for therapeutic as well as diagnostic purposes and include recombinant proteins, antibodies, vaccines, blood factors, hormones and many other types of substances. Currently, there are more than 200 biologics on the market and they account for almost a third of all pharmaceuticals under development.

These unique substances revolutionized the pharmaceutical industry and brought tremendous improvement to the treatment of many medical conditions. They also brought their own set of challenges in manufacturing, quality control and regulations. Most biopharmaceuticals are developed by using recombinant DNA technology, where specific proteins are produced by genetically engineered cells.  As such, biologics are very sensitive to changes in the production process and they are more difficult to characterize than synthetic drugs. Even small changes in manufacturing conditions or cell lines can cause considerable variations in final product, causing differences in therapeutic action. That is why, unlike with synthetic generic drugs, biosimilar compounds require clinical trials to prove the drug equivalency.

All cell lines require media to grow and function. Cell culture media have complex composition that needs to be optimized to ensure proper functioning of the cell lines. The type of media needed would depend on the manufacturing process mode as well as stage of cell line life. For example, media needed for optimum cell growth would be different from the one required for optimized production rate of the final product. Optimum cell media should be able to sustain high cell density and maximized production yield.

Amino acids, being the building blocks of proteins, are necessary ingredients of all cell culture media. Since cells can’t synthesize essential amino acids, they must be included in the media to ensure cell propagation and functioning.  L-Glutamine is one of the most important essential amino acids since it serves as a Nitrogen source as well as energy source for cell metabolism. Non-essential amino acids also get depleted during cell line lifetime, so supplementation of such amino acids as L-Proline, L-Serine and L-Alanine is also necessary. Monitoring amino acids at various stages of the manufacturing process ensures viability of the cells and high quality of the final product.

Due to complexity of composition and structure, biopharmaceuticals are challenging to characterize. A wide array of methods, such as immune assays, gel electrophoresis, different chromatographic and mass spectrometric techniques are used in combination to fully confirm the substance purity and identity. The ICH Q6B is a guidance document that provides a set of internationally accepted specifications for biotechnological and biological products to support new marketing applications. ( Determining amino acid composition following hydrolysis is listed in Q6B as a way to characterize the protein and to confirm its identity by comparing with the amino acid composition deduced from the gene sequence of the desired product. Amino acids analysis data is also used to accurately determine the protein content.

Pickering Laboratories offers methods to analyze amino acids in hydrolyzed protein samples and well as cell culture media. See our application notes 373 and 371 for more information.


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