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Polyether Antibiotics Method Spotlight

Cows eating grainPolyether antibiotics, such as Monensin, Salinomycin, and Narasin, also referred to as ionophores, are widely used to control coccidiosis in poultry and to promote growth and increase feed efficiency in cattle. Ionophores reduce the number of gram-positive bacteria that favor fiber fermentation in the rumen thus increasing the number of gram-negative bacteria that favor starch fermentation.  That changes the profile of bacteria-synthesized volatile fatty acids, improving energy intake from feed. Since ionophores have a narrow safety range and are toxic in case of overdose or if fed to sensitive species, medicated feeds, premixes, and supplements are strictly regulated.

Analysis of polyether antibiotics using post-column derivatization with Vanillin in an acidic environment is the basis of several AOAC official methods for feed analysis. Advantages of using this approach include wide analytical range, easy sample preparation, and superior accuracy and reproducibility of analysis.  Post-column derivatization is especially useful for analysis of fairly high concentrations in feeds and premixes since the methods wide analytical range and absence of matrix interferences allow to avoid excessive sample dilution therefore improving accuracy of the results.

Several years ago, researchers from UC Davis presented a study at American Association of Veterinary Laboratory Diagnosticians (AAVLD) annual meeting comparing the use of LC/MS methods and post-column derivatization methods for analysis of polyether antibiotics in feeds and biological samples. The group has demonstrated that while LC/MS methods were sensitive and performed well for trace analysis, they presented a lot of challenges when applied to feed samples. Poor chromatography, matrix interferences, poor linearity of the response, and narrow analytical range led to up to 30 % RSDs and considerable deviation from expected values for feeds and pre-mixes. Contrarily, all these problems disappeared when the feeds were analyzed using post-column derivatization with Vanillin. Validation results showed low variability of the results with less than 4 % RSDs for spike recoveries and feeds analysis, wide calibration range from 10-2000 ug/mL (vs 0.1 – 1 ug/mL for LC/MS) and good correlations with expected values.

Pickering Laboratories’ Onyx PCX post-column derivatization system is uniquely suited for highly acidic reagents due to the fully inert flow path and automatic pump flush capabilities. In addition to the post-column derivatization system, we offer highly purified Vanillin and an analytical column tested to ensure separation of Monensin A and B as well as Salinomycin, and Narasin.  Pickering’s method can easily be implemented in any feed laboratory and used to run analysis of medicated feeds and supplements according to official AOAC methods. The same post-column system and HPLC instrument can be utilized for analysis of amino acids in feeds.

Maria Ofitserova, Ph.D.
Senior Research Chemist
Pickering Laboratories, Inc.
1280 Space Park Way
Mountain View, CA 94043, USA
maria_o@pickeringlabs.com
Phone: (650) 694-6700 x703

Cannabis Cultivation Contaminants by Photochemical Derivatization

By Maria Ofitserova, PhD.

Cannabis leavesAnalytical laboratories are faced with the task of expanding their testing capabilities to meet the Cannabis Industry’s regulatory requirements as the number of States that legalize Cannabis increases. Without clear Federal regulations, testing requirements differ between States, however, most require to test Cannabis and Cannabis-containing products for potency as well as contaminants such as heavy metals, residual solvents, pesticides, and mycotoxins.

Cannabis cultivating conditions are known to promote the growth of mold and Aspergillus species, a common source of contamination in plant material. Aspergillus are the main fungi that produce Aflatoxins and Ochratoxin A so it is not surprising that these mycotoxins are on the list of regulated contaminants in most States.
Aflatoxins are known carcinogens and due to their stability, they easily persist through processing and can carry not only into dry plant products but also into various extracts and edible goods. Aflatoxins B1, G1, B2, and G2 are especially dangerous to humans and inhaling or ingesting them, even in low doses, over a period of time can cause chronic diseases and cancers.

Since many States have established regulatory limits, not only for total Aflatoxins but also separately for Aflatoxin B1, HPLC methods offer the perfect approach to analyze Mycotoxins in Cannabis and Cannabis products. Separation of Aflatoxins B1, B2, G1 and G2 as well as Ochratoxin A is easily accomplished on a reversed-phase column and the addition of a photochemical reactor increases sensitivity of detection for Aflatoxins B1 and G1 and allows to readily meet even the strictest regulatory limits.

Pickering Laboratories has demonstrated that the simultaneous analysis of Aflatoxins and Ochratoxin A in Cannabis and different types of Cannabis-containing products can be successfully accomplished by HPLC with photochemical derivatization and fluorescence detection. Sample preparation using a single immunoaffinity cleanup column, utilizing Mycotoxin selective antibodies, allows for eliminating interferences and concentrating Mycotoxins to increase the sensitivity of analysis. The same method can be used for the analysis of hemp plant material and extracts and hemp-containing products. This approach has a proven performance for many commodities and is the basis of AOAC 2008.02 official method for analysis of Aflatoxins and Ochratoxin A in Ginseng and Ginger.

Maria Ofitserova, Ph.D.
Senior Research Chemist
Pickering Laboratories, Inc.
1280 Space Park Way
Mountain View, CA 94043, USA
Email: maria_o@pickeringlabs.com
Phone: (650) 694-6700 x703

On the Road Again

Technical Support Chemist, Maria Ofitserova

Maria Ofitserova, Senior Research Chemist

Kevin McKeown, Sales Manager

Kevin McKeown, Sales Manager,

Rudy Suez, Customer Service Manager

Rudy Suez, Customer Service Manager

David Mazawa, Technical Support Chemist

David Mazawa, Technical Support Chemist

 

Pickering Labs was extremely excited to start hitting the trade-show circuit again, after an enduring a LONG absence since Pittcon 2020. Our Customer Service Manager, Rudy Suez, and Technical Support Chemist, David Mazawa, attended the NEMC Conference in Bellevue, WA in early August. Our Senior Research Chemist, Maria Ofitserova, and Sales Manager, Kevin McKeown, attended the AOAC annual show in Boston in late August. It was a joy to see our customers face-to-face (mask-to-mask?!) again and do a reintroduction of our Onyx PCX instrument. Upcoming shows where you can see Pickering Labs include ACIL in Long Beach, CA in early October and AATCC (American Association of Textile Chemists and Colorists) in Raleigh, NC in mid-November. 
      

Kevin McKeown
Sales Manager
Pickering Laboratories, Inc.
1280 Space Park Way
Mountain View, CA 94043, USA
Email: rlsmith@pickeringlabs.com
Phone: (302) 229-5928

Product Spotlight – 1700-0324

Artificial Saliva bottleProduct Spotlight – 1700-0324, Artificial Saliva with Mucin
(950 mL)

Responding to overwhelming demand, Pickering Labs has introduced our Artificial Saliva with Mucin in a new, larger 950 mL size! This solution has been in the spotlight recently, as ASTM E2720-16/ASTM E2721-16 specifies decontamination procedures for surfaces and materials contaminated with human pathogenic viruses. The formulation has a mineral composition and pH close to human saliva and contains Mucin to increase the viscosity and lubricating ability of the solution. This artificial saliva can also be used for dental, drug delivery and pharmaceutical studies. Research into COVID transmission is a major focus for the whole world at present and Pickering Labs is proud to supply products that aid in this research.
  
Kevin McKeown
Sales Manager
Pickering Laboratories, Inc.
1280 Space Park Way
Mountain View, CA 94043, USA
kmckeown@pickeringlabs.com
Phone: (302) 229-5928

Milestone Anniversaries

We are very fortunate at Pickering Labs to have MANY hard-working, long-term employees in our midst! Just this past year we have had cause for celebration, honoring the below BIG-TIME anniversaries: 

Jim Murphy, President and Gloria Garcia, Customer Support – Celebrating 30 yearsJim Murphy, President and Gloria Garcia, Customer Support – Celebrating 30 years

Jim Murphy, President and Gloria Garcia, Customer Support – 30 years
    

Maria Ofitserova, Sr. Research Chemist celebrates20 years

Maria Ofitserova, Sr. Research Chemist –
20 years

Anita Gribaldo, Packaging & Production Support celebrates 20 years

Anita Gribaldo, Packaging & Production Support – 20 years

Gabriela (Gaby) Ron, Production Chemist celebrates20 years

Gabriela (Gaby) Ron, Production Chemist –
20 years

Ed Cowan, Instrument Assembly celebrates 20 years

Ed Cowan, Instrument Assembly – 20 years

 

We like any excuse to throw a party around here (especially after the past 1 ½ years!) and having all these big milestones occur this past Summer really allowed us to have some fun. Please join me in congratulating all of these Pickering employees who have given so much to the company.
      

Rebecca Smith
Vice President
Pickering Laboratories, Inc.
1280 Space Park Way
Mountain View, CA 94043, USA
rlsmith@pickeringlabs.com
Phone: (650) 694-6700 x727

Chromatography Quiz #39 – Rising Baseline

Chromatography Quiz #38 —  Troubleshooting High Pressure — Winners

Pickering Labs would like to congratulate all of our winners for our previous newsletter’s Chromatography Quiz:

pumpkin basket with baked goods and wine

Josiah Hakala from Minnesota Department of Health, Tom Schneider from Suffolk County Water Authority, and Narjes Ghafoori from Los Angeles County Public Health Laboratory.

Winners will soon receive a Pumpkin-Shaped Gift Basket! Includes an assortment of baked goodies, sweet treats, and a bottle of red blend wine! ($99 value) Happy Autumn!

Congratulations to our quiz winners!

Thank you all for your submissions!

The correct answer to the Troubleshooting High Pressure Quiz was beautifully summarized by Tom:

The blockage is located between the union and the inlet to the detector.  The largest pressure drop occurs when the outlet of the union is disconnected.  Since the inlet to the detector does not show a significant decrease in pressure, the tubing that connects the union to the detector is the cause of the high back pressure and should be replaced.

Chromatography Quiz #39 – Rising Baseline

What is causing the Carbamates baseline to rise? Below you will find a reference chromatogram, HPLC gradient table, and bad chromatogram.

Bad Chromatogram Example

Bad Chromatogram

Good Chromatogram

Good Chromatogram

Method 1: lists conditions

Correctly identify the chromatography issue and win a prize! Simply email your answer and your full contact information to Rebecca at rsmith@pickeringlabs.com by November 30, 2021 in order to win. You will receive email confirmation when your submission is received, and the troubleshooting answer and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission).

If you have difficulty reading the images for Quiz #39, please click on them to enlarge or contact David Mazawa below to obtain a more user friendly PDF.

David Mazawa
Technical Support Chemist
Pickering Laboratories, Inc.
1280 Space Park Way
Mountain View, CA 94043, USA
david@pickeringlabs.com
Phone: (650) 694-6700 x710

 

 

 

 

 

 

 

 

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