All posts by Pickering Laboratories

Quiz #43 June 2023

Polyether Antibiotics are commonly used for preventing coccidiosis and other infections in poultry and for improving feed efficiency for beef cattle and swine. The use of Polyether Antibiotics is strictly regulated, with only specific ionophores approved for use in feeds intended for different animals.

Analysis of Polyether Antibiotics by HPLC with post-column derivatization and UV/Vis detection has been proven to successfully identify and quantify Monensin, Narasin and Salinomycin in medicated feeds, supplements and premixes as well as to determine trace contamination levels in non-medicated feeds.

Post-column derivatization of Polyether Antibiotics is done using highly acidic Vanillin or DMAB reagents. The Onyx PCX derivatization system (Pickering Laboratories, Inc.) has an inert flow path and automated system wash capabilities that make it uniquely suitable for handling corrosive reagents. The two-pump system is recommended to extend reagent stability, but the single-pump system for this application is also available.

Adding a Fluorescence detector to the instrumentation allows for using the same extraction procedure and HPLC conditions to also determine Lasalocid, which doesn’t require post-column derivatization.

The method details can be found on our website here.

The typical flow diagram for the Polyether Antibiotics post-column system is shown here:

Good Chromatogram:

Bad Chromatogram:

What could be contributing to the loss of signal?

Submit your answers to by Friday, September 1, 2023.

Pickering Laboratories would like to congratulate the winners for our previous newsletter’s Chromatography Quiz #42:

Thomas Schneider from SCWA, Narjes Ghafoori from Los Angeles County Public Health Laboratory, and Josiah Hakala from Minnesota Department of Health. 

They each will soon be receiving a Nike $100 Gift Card!

Congratulations to our quiz winners!  Thank you all for your submissions!

Chromatography Quiz #42 Solution:

Natural human perspiration has a complex composition that depends on the type of sweat gland, the person’s metabolism and hydration level. Pickering Laboratories’ human mimic artificial perspiration solutions are formulated based on published data for human sweat and provide the closest match to the “real thing” available on the market. These solutions are perfect for testing a variety of consumer products and medical devices as well as for forensics applications and as blanks for medical testing protocols.

  • There are two types of human perspiration; Eccrine and Apocrine
  • Eccrine perspiration is used for body temperature regulation.
  • Eccrine perspiration contains amino acids, minerals, and metabolites.
  • Pickering Laboratories’ proprietary Artificial Eccrine Perspiration comes at pH 5.
  • Apocrine perspiration is secreted by apocrine glands and contains fatty acids and proteins.
  • Apocrine perspiration is initially odorless. Odor (volatile fatty acids) is produced once acted upon by bacteria.
  • What is an oily substance that mixes with lipids to form a protective coating on the skins surface?
    1. Sebum
    2. Cerumen
    3. Perspiration
    4. All of the above
  • Currently, Pickering Laboratories offers the following product testing solutions:
    1. Perspiration
    2. Blood
    3. Saliva
    4. Lung Fluid
    5. All of the above
  • The pH of the solution is an important consideration in product testing, affecting corrosion rate, level of color degradation and leaching of metals and organic components from wearable products. Many procedures require a tight pH range during testing. To accommodate these pH requirements and to improve pH stability over time, Pickering Laboratories is offering buffered versions of industry-specific artificial perspiration formulations. By adding a Phosphate buffer to the original formulation, the pH stability of the solution is greatly improved while its effect on corrosion and colorfastness remains unaffected.
  • _____________ is one of the most important concerns in the textile industry. Discoloration of fabric can be due to perspiration, light, rubbing or a combination of all three. Salt, urea and lactic acid present in sweat can disrupt the bonding that dyes form with the fabric fibers, causing fading of the color. In addition, amino acids in sweat can attach to fabric to produce “protein stains”.
    1. Dissolution
    2. Staining
    3. Corrosion
    4. Colorfastness
  • Use of nanotechnology to endow new properties to textiles, such as antibacterial or UV protection, water repellency or flame retardancy, together with incorporating sensors and other digital components, creates the need to consider the effects of sweat on nanoparticles leaching and _____________ of integrated circuits as well.
    1. Corrosion
    2. Rusting
    3. Colorfastness
    4. Dissolution
  • A Certificate of Analysis (COA) and Safety Data Sheet (SDS) are available for all product testing solutions at no additional charge. True
  • Pickering’s product testing solutions and mimics are convenient, save you time, homogenous, reproducible, and customizable. True
  • Pickering offers customizable versions of our product testing formulations. True
  • Pickering Labs will be at booth 2138 at Pittcon 2023. True

New Product Spotlight: Synthetic Soil

Synthetic Soil according to AATCC LP4-2023

Synthetic soil is used as the soiling option for evaluations of stain and soiling related to pile yarn floor coverings. The official methods that are used for these evaluations are AATCC TM122, AATCCTM123 and ASTM D6540. The procedure to apply the test soil is being improved to make it reproducible, and this has changed the status of some of the methods. Regardless, the synthetic soil used to soil or stain the floor covering has remained the same. The ingredients used and the procedure for formulating the synthetic soil is now available as AATCC LP4-2023. The Pickering Laboratories Synthetic soil (1700-0706) follows this procedure, sieved using 200 mesh sieve and is available in 25 g quantities. This formulation can also be used in other product testing procedures that require the use of synthetic soil.

1700-0063 Carbamate Test Mixture Update

Carbamate Test Mixture in Methanol, 2.5 μg/mL, each (1.0 mL /bottle) – PN 1700-0063

Please take note that part number 1700-0063 Carbamate Test Mixture will be undergoing a packaging change. The new final volume will be 1.0 mL rather than 5 mL. This packaging update will alleviate the need to ship Carbamate columns (which include the test mixture) as “Dangerous Goods in Excepted Quantites.” The new final volume will be considered De Minimis and does not need to ship as a regulated material. Additionally, the test mixture will now come packaged in an HPLC vial and be ready for injection directly from our packaging.

The following packaging change will take effect on July 1, 2023.

1700-0063 Carbamate Test Mixture in Methanol, 2.5 μg/mL, each (1.0 mL /bottle), Aldicarb, Aldicarb Sulfone, Aldicarb Sulfoxide, BDMC (4-Bromo-3,5-dimethylphenyl-N-methylcarbamate), Carbaryl, Carbofuran, 3-Hydroxycarbofuran, Methomyl, Methiocarb, 1-Naphthol, Oxamyl, and Propoxur

Please contact Pickering Laboratories Support at (650)694-6700, (800)654-3330, or if you have any questions.

NACRW – Sareeta

Who says that only David and I get to have all the fun at exhibitions and trade shows?!  Our very own Research Chemist, Sareeta Nerkar, will be in attendance at the annual NACRW – North American Chemical Residue Workshop – in beautiful Fort Lauderdale, Florida the last week of July.  Sareeta has been a long-time attendee of this show, with Pickering Labs a decades-long supporter and exhibitor prior to her involvement.  We always find it a very valuable resource for keeping an eye on emerging trends in environmental contaminants and other concerns.

This year, Sareeta is the co-chair of the NACRW program (General Session), as well as Secretary for the Organizing Committee. In addition to her work as part of the volunteers supporting the event, she will also be presenting her poster on the Analysis of Formaldehyde in Cosmetics and Other Personal Care Products.  We are making a conscious effort to find novel methodology and new applications which can benefit from a Post-Column reaction; Sareeta is at the forefront of this research.  A snippet from our new Method Abstract outlines the importance of this testing:

Formaldehyde and formaldehyde-releasing agents are widely used in manufacturing of building materials, cars, plywood, polymers, glues and adhesives. It is also commonly used in household items, personal care products and cosmetics as a preservative and disinfectant. Due to high toxicity and suspected carcinogenicity the products are tested to determine free formaldehyde content and ensure the safety of the consumers. Testing is also important to monitor production of resins and other polymers and to ensure the quality of final materials.

If you are lucky enough to also be in sunny Fort Lauderdale, Florida, please stop by and say hello to Sareeta!


Back in Action – Pittcon 2023

By Rebecca Smith

As the Pickering team mentioned in our last newsletter, we were humming with anticipation in the lead-up to attending Pittcon 2023.  The conference returned to in-person in March for the first time, post-pandemic, and we jumped at the chance to get to Philadelphia.  Kevin McKeown, David Mazawa and I happily hopped on two planes and a train for the trek and immersed ourselves in a week of reuniting with longtime customers and meeting new attendees as well. 

Kevin and Rebecca looking WAY too excited to be out in public…

Although many of our international distributors were still unable to travel, we did have a good showing of North, Central and South American dealers arrive for meetings and to enjoy the expo.  For some of these relationships, this is the first time Kevin was able to actually shake hands and say “hi!”  He’s been Pickering’s Sales Manager for coming up on three years this November; that’s a long time to maintain new relationships virtually.  The meetings were all fantastic!  We appreciated each of our resellers who made the trip and hope to enjoy the mutual benefits of our ongoing partnerships.

Kevin has been in the industry a long time, and he’s got a huge network of existing relationships to tend to as well.  David and I went with him to our first Independent Laboratory Distributors Association (ILDA) reception, but he’s been an active participant for over a decade.  It was good fun (and food) for sure!

David, meeting new people at the ILDA opening reception.

As with every exhibitor, we brought plenty of giveaways and literature for attendees to enjoy (and hopefully learn more about Pickering).  This year, our 40th anniversary insulated/reusable shopping bags were a big hit!  It was so nice to celebrate our belated anniversary in Philadelphia with the entire expo, now that we’ve moved back to a live conference environment.  The bags are right in theme our other big 40th anniversary activities, including our timeline.  If you missed seeing this last year, it’s well worth a read!  We’ve been involved in a lot of great stuff over the last four decades.

In another of our traditional Pittcon celebrations, we also raffled several prizes.  These gadgets are often products associated with our Product Testing Solutions (PTS) line, which are used in consumer product testing and development.  It’s our small way of thanking both our PTS customers and our Pittcon booth visitors!

This year, we’d like to congratulate winners Jim Walla from Evonik, and Julio Ogedra (pictured below) from the University of Central Florida.  We hope they both enjoy their prizes!

Kevin, seen posing with one of our excited raffle winners!


By: Kevin McKeown

In May, Pickering Labs had a chance to exhibit at the LAPRW – Latin America Pesticide Residue Workshop –  in Panama City, Panama!  This was made possible by an invitation from one of our Central American dealers, Analytical Technologies, and we are very grateful for the partnership (and translation services, even though Technical Support Manager David Mazawa’s Spanish is passable!).  Our booth was shared with other companies that Analytical Technologies represents: Agilent and Gerstel. 

The show consisted of many hot topics in the Pesticide Residue testing world, including the continued importance of Glyphosate monitoring.  Pickering Labs has been a leader in Glyphosate/Carbamate analysis for over 30 years, so it certainly gave us a lot to talk about with the attendees!  Some of the more interesting requests that we were asked about were Glyphosate in Honey and in Tomato Leaves.  Using HPLC + Post-Column is not only a long-standing, tried and true way of doing this analysis, but is also completely matrix-independent: making a tricky substance like honey a perfect candidate for our instrumentation.

What would a trip to Panama be without a trip to the canal?!  David and I had a VERY early Sunday morning wakeup call so that we could squeeze in some sightseeing, which included a bicycle tour around “old town” Panama City, where we learned a lot about Manuel Noriega and the completed history of Panama.  The organizing committee for LAPRW put together a wonderful show, which included a performance of traditional dancing, in classical dress, by some of the LAPRW volunteers (truly a full-service group!).  I would be remised if we did not get the attached picture with a pair of the dancers in front of our beautifully-appointed booth.


Letter of Authenticity

Pickering Laboratories, Inc. has recently become aware of a concerning issue in regards to copycatting of our products, both Post-Column and PTS (artificial body fluids). We have heard from our international distribution partners that there are inferior manufacturers who are actively looking to misrepresent their products as being produced by Pickering Laboratories, Inc. Some of their tactics include: mimicking our label, copying our company logo and most-brazenly stating that their company has acquired Pickering Labs, Inc.

None of these claims are accurate. In addition, these ‘spoofed’ products are not actually manufactured to the same formulations, nor are they produced with the same quality as Pickering Labs authentic products.

Our authorized dealers in each country can be found at the following website:
In addition to being listed on our website, you can request an “Authorized Distributor Certificate” or a “Letter of Authorization” from any dealer to ensure that you are truly getting products manufactured by Pickering Labs.

We encourage any purchases to solely be made through distributors listed on the above link and we would like to thank our partners for bringing this to our attention.

If you, as an international customer or end user of Pickering Labs products, have any hesitancy at all in regards to a purchase we encourage you to contact us directly at: or We will be happy to answer any questions or review a possible source for authenticity.