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.


Free-Range Parenting, Pasture-Raised Eggs and No Antibiotics Ever Chickens

By Rebecca Smith

As most of you know, Pickering Labs is a small company.  We all work on a single shift, so pretty much everyone is in the lunch room at the same time each day.  That makes for a wide range of conversational topics daily, which are often influenced by the San Jose Mercury newspaper on the table or the contents of the local news the evening before. 

When Utah passed their “Free-Range Parenting” law, it made national news back in March.  It also made conversation in the Pickering breakroom!  We discussed the definition provided for free-range parenting and concluded that here at Pickering we needed more options for defining parenting styles.  Enter the new supplemental phrases: cage-free parenting and pasture-raised parenting!  Taken from the Humane Farm Animal Care Standards, we decided that a cage-free child was the most closely supervised, followed by a free-range child (allowed some autonomy) and finally a pasture-raised child, which was given the most license to roam.  It’s interesting that although most of us considered ourselves to have been pasture-raised in our childhoods, many of the staff employed a more cage-free or free-range style when raising their own children. 

As Saji, Anita and Gabriela discussed the pros and cons of degrees of parental supervision (while giving David plenty of advice for raising his 15-month old daughter), I wondered what impact the ‘parenting’ differences had on the hens and their eggs…  It was lunchtime after all! 

It appears that pasture-raised eggs might have health benefits over commercially-raised eggs, including increased omega-3 fatty acids, vitamin E, vitamin A, and beta carotene.  They also have reduced cholesterol and saturated fats, both of which the American Heart Association recommends reducing in your diet to lower your risk of heart disease and stroke.  The differences in the eggs come from the chickens’ diet: pasture-raised hens eat grass and bugs in addition to the grain feed given to commercially-raised hens.

So, while we’re talking about the chickens’ diet and lifestyle, what else can contribute to the health and wellbeing of these hens?  After additional research, I discovered that poultry farming comes with its own bill of rights!  Called the Five Freedoms for Poultry, chickens are raised humanely when their basic needs are met (food, water, safety) but they are also given the freedom to express their natural behaviors and they have rapid access to diagnosis and treatment of injury or disease. 

Now I’m onto something!  But does a happier chicken make a tastier egg, or just a healthier one?  It’s hard to find scientific studies on taste, although you can find loads of data on the differences in composition of meats raised in different ways.  Composition impacts how healthy the egg is, but when it comes to its actual taste, apparently the mindset of the person tasting and the color of the egg might have more bearing on perceived taste than anything else, including whether the hen was pasture-raised or conventionally-raised. 

Even if taste isn’t a factor, purchasing healthier eggs and meat coming from happier hens can still be a worthwhile grocery shopping practice!  Top concerns include the environmental and human health effects of antibiotics use in the production of food, a topic that has gained steam in consumer awareness in more recent years and has been studied for several decades internationally.  As the public increases its attention on antibiotics use and antimicrobial resistance, farmers are beginning to make changes to the manner in which antibiotics are used in livestock farming.  And for good reason, as their livelihood could face increased pressure from the eventual market introduction of synthetic or lab-grown meats

In response to consumer concerns regarding food production, moving away from antibiotics use became a top priority for Perdue Foods, one of the biggest poultry producers in the United States.  Perdue began the process of raising poultry without antibiotics fifteen years ago, and they have hit a major milestone with 100% of the birds they produced in 2017 raised “No Antibiotics Ever,” meaning that from hatchery through slaughter, the birds are never treated with any antibiotics during their lifetime.  If the use of antibiotics become medically necessary for a bird, the animal is treated as needed but removed from Perdue Foods branded production.  All human and animal antibiotics have been removed from the feed and hatchery, and animals are raised in a way that does not require antibiotics for disease prevention. 

In fact, remember the Five Freedoms of Poultry?  Perdue continues to improve their implementation of the Animal Care Initiative, adding windows and enrichments to encourage bird activity.  Says Mike Leventini, manager of live production activities at Perdue Foods: “We believe an active chicken is a healthy chicken, it simply goes hand in hand.”  An impressive philosophy to implement for a company that processes 13 million birds per week from over 2,100 farms around the United States! 

Did you know Pickering Labs services the animal feed industry?!  We offer post-column methodology, instruments and consumables for the analysis of polyether antibiotics in animal feeds as well as the analysis of aminoglycoside antibiotics in feeds and the analysis of sugars in feeds.  We are also continuously improving our amino acids analysis in feeds and offer a wide range of post-column methods for oxidized and unoxidized feed samples

Most recently, our R&D team released a fast and sensitive method for the analysis of fumonisins in grains and feeds, which is particularly of interest due to the health problems caused in horses and swine.  You might remember our contaminated feed concerns from a previous newsletter article which discussed the risks of mycotoxins to livestock. 



Omelets and Pressure

By Saji George

There is a saying, “one cannot make an omelet without breaking a few eggs”. What do omelets and eggs have to do with post-column instrumentation? No direct correlation, but both have an underlying parameter that is important in achieving the final goal. Too much pressure on the egg and you will end up with egg shells in your omelet, too little pressure and there might not be an omelet.

In the case of the post-column derivatizer, there is a sweet spot (pressure range) that relates to a system that is working well. The system pressure is mostly comprised of the reagent pump(s) pressure(s) and gives an idea of how the overall system is performing. Too high and there is a constriction problem, too low and there is a leak in the flow path.

The pump pressure measures the pressure downstream from the pressure transducer. This includes the heated reactor, filters, unions, detector, and flow path tubing. All of these components have to be looked into when troubleshooting a high pressure problem. The best troubleshooting method is to remove one component at a time to look for the pressure drop; it is best to work backwards (start from the outlet of the detector). Components to pay attention to are: back pressure regulator, detector, ambient reactor, heated reactor, restrictors if there are any and last but not least the reagent filters. A significant drop (greater than 100 psi) in pressure when one of the components is removed would indicate that it is the source of the problem. The same thought process works for leaks also! Take a lint free towel and wipe all connections one by one, looking for areas of wetness that would indicate a leak.

Since summer is around the corner and graduations, admissions applications and final exams (to name a few) have been taken care of, please do take time to hit the sweet spot by enjoying the great outdoors!  

Pittcon News and Notes

By Mike Gottschalk

The 68th Pittcon International for 2018 was hosted in Orlando, Florida which provided a welcome respite from February’s wintery embrace to many a northerner. Beside the welcoming venue, the programs and exhibitors continue to contribute to the leading exhibition for laboratory science and new technology in food safety, life science and emerging markets.

Pickering Laboratories presented the latest method advances in our Post-Column Applications and received significant interest in our recently introduced Product Test Solutions from a diverse audience of conference attendees.

New from Pickering for Pittcon this year was our post-column application for Cannabinoids Analysis in Cannabis Plants and Edibles, Amino Acid Analysis in Foods and Supplements as well as several new formulations of Product Testing Solutions.

We are always surprised at the variety of companies interested in our product testing solutions: credit card manufacturers, tobacco companies, electronics manufacturers, surgical instrumentation companies, materials scientists, pharmaceutical companies, and makers of musical instruments to name a few. These different industries have all found the quality and consistency of Pickering’s product testing solutions to offer the reliability they need for performing product development and ongoing quality assurance testing.

To add to the excitement of our new products, we held daily raffles for an Apple Watch and two Bose Soundsport Pulse headphones. Congratulations to our three winners!

Not only were the winners of the raffle prizes excited, but passersby generated quite a buzz checking out this year’s playful Pickering promotional handouts, including: Fidget Spinners, Emoji Pens, Lab Rulers and Workout Towels. We enjoyed engaging with our visitors and we appreciated those who stopped to learn more about what Pickering Labs offers!

Thank you for visiting our booth at Pittcon!  And if you missed us, our next show is the North American Chemical Residue Workshop (NACRW) in Naples, Florida from July 22 through 25, where you can be sure to see myself and Sareeta Nerkar and pick up some application notes (or another emoji pen)!


Chromatography Quiz #29

Chromatography Quiz #28: 35th Anniversary Word Puzzle – Results

Pickering Labs would like to congratulate all of our winners for our previous newsletter’s 35th Anniversary Word Puzzle: Jim Balk from Nebraska DHHS Public Health Environmental Laboratory, Tom Schneider from Suffolk County Water Authority, Karissa Scroggins from North Coast Laboratories, Narjes Ghafoori from LA County Environmental Toxicology Lab, Joy Gottlieb from New Mexico Department of Health Scientific Lab Division, Hossein Hajipour from Texas Dept. of State Health Services Laboratories, and Widchuda Meeim from Thailand Bureau of Quality Control of Livestock Products.

Winners will soon receive a Packing Organizer Set from the Container Store! This colorful set of 6 packing cubes are durable and clearly labeled to help you organize your suitcase! Just in time as you plan for those summer getaways!

Congratulations to our quiz winners and happy packing!

Thank you all for your submissions! 


The correct answers for the Anniversary Word Puzzle are as follows:

Chromatography Quiz #29 – Amino Acids Elevated Baseline:

Simply email your answer as well as your full contact information to Rebecca at by July 15, 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). 

Maroon: Good chromatogram

Blue: Elevated baseline

What could be contributing to the elevated baseline?




How It All Started

By Judy Pickering

Four years into our 40-year marriage, I can recall Michael saying “I know I can improve amino acid analysis” with such enthusiasm it could only mean big things.  He’d finished up his second post-doc and was working in industry – a startling contrast, to be sure, but moving every year was increasingly difficult with our growing family.  So, we settled in the Bay Area permanently and he started first with Durham Instruments and then worked for Spectra Physics.  At the time, amino acid analysis was taking chemists on the order of 12 hours per run!  Reducing the run time to three hours was only the first of many developments Michael had up his sleeve. 

Within the year, Michael left his job to start Pickering Laboratories with our flagship product: Trione®, our ninhydrin reagent.  The first bottles were sent out to industry experts for evaluation, and became our ambassadors carrying with them our hope of building a successful business.  I remember it was important to Michael for the bottles of Trione® to ship upright, because he thought of them as little soldiers marching off to the marketplace to do the job of defending his reputation and building our brand.

The early days of the business were challenging.  Michael did all the phases of production, taking orders as well as all of the manufacturing, packaging and shipping.  He even “hired” our two older kids to wash the bottles sometimes.  I was working in corporate marketing at the time, so I would attend trade shows and help Michael network with potential customers.  We didn’t want people to know we were such a small company, so I used my maiden name to give the appearance I was an employee instead of his wife!

Michael at One of Our Early Booths.

When Michael would talk to chemists about Trione®, they would get so excited about this breakthrough reagent for amino acids analysis.  We were always grateful so many people offered their advice and counsel just to help the enterprise along.  It was rough-and-tumble for the first year or two, and every encouraging word helped keep us going.

Customer orders began building momentum, and Michael and I breathed a sigh of relief!  Michael hired an additional 3-4 people on staff and I quit my job to help with administrative duties and expanding our marketing efforts.  He determined there was demand for a post-column derivatization instrument, and the PCX5000 was born.  Our earliest foray into instrumentation came as a benchtop kit, with standalone components including a pump, mixing system and reactor. Michael initially didn’t want Pickering Labs to be an instrument company, but we found that the instruments were needed to support the sale of our Trione® reagent and also the growing family of buffers we were selling.

Michael and Our Oldest Daughter in Front of Our First Building.

Michael’s reputation for post-column expertise began gaining attention from other chemists whose applications were post-column but not amino acid analysis.  As a result, Michael began to explore these other industries’ post-column needs.  And when he developed Pickering’s OPA-reagent-based products for analysis of Carbamates and Glyphosate, he entered into the world of environmental testing and began working with EPA methods.  Chemists who had previously been making their own eluents by following the EPA methods could now buy Michael’s ready-to-use buffers and purified reagents instead.  And they kept reordering because of the quality and reproducibility that Michael’s chemistry delivered. He would even say that he would “guarantee the chromatogram” to any chemist using his products, which was unprecedented. 

With the administrative/office duties securely staffed and the business looking more and more like a successful enterprise, I stepped back into a part-time role and focused on marketing.  As our family expanded, my time also became more occupied at home (our two youngest daughters were born in the mid-80’s).  By the end of the eighties, Michael was ready to hire additional staff to manage the business so he could really focus on his true passion: research and product development. 

In fact, as I think about that time, the early nineties are when the company really started to take shape in its modern form.  Michael added then-Operations-Manager Jim Murphy to manage the business in 1991 (Jim is our current President) and shifted fully into a technical role.  They also hired a full-time marketing manager, and so I went to work soon thereafter for the Palo Alto school district. 

Michael and his team evolved the PCX5000 standalone kit into the PCX3100 and PCX5100, our first fully-integrated post-column derivatization instruments.  Michael also developed more post-column applications with the collaboration of EPA, FDA, AOAC and CDFA, all of which further expanded our chemistries and columns offered.  Which in turn cemented our customer base and reputation for making the post-column instruments.  The business experienced steady growth, and the PCX3100 and PCX5100 sold well and supported our chemistry sales exactly as we’d envisioned.

Pickering Labs celebrating its 35th anniversary is a wonderful chance for me to reflect on working so closely with Michael during the first ten years of the business.  And I’d like to use our newsletter as an opportunity to introduce myself, or reintroduce myself to our long-time customers.  After my retirement from the school district, I began getting involved in the business again and joined the Board of Directors in 2014.  My work with the Pickering team behind the scenes isn’t very visibile to our customers, but I hope this gives us an opportunity to remember Michael together and that you enjoy my fond recollections (and new perspective?) of how Pickering Labs began.

Michael and Judy Pickering,
Back When It All Started.

Guaranteed Chemistry