Bread Rises

SF-SourdoughRising to the Occasion
Michael Pickering

My wife Judy baked bread recently for our annual St. Patrick’s Day luncheon at Pickering Labs.  She’s an excellent baker, and her Irish Soda Bread is a favorite addition to the corned beef and cabbage “traditional” fare.  Soda bread uses baking soda instead of yeast as the rising agent for the dough.  In addition to baking soda, her recipe also calls for flour, salt, and buttermilk.  This is typical for soda bread, as the buttermilk contains the lactic acid required for the ‘rising’ reaction with the sodium bicarbonate. 

Having grown up in Southern California, I have fond childhood memories of another special kind of bread – Salt-Rising Bread.  This denser bread relies on the fermentation of salt-tolerant bacteria in cornmeal.  The cornmeal must be freshly stone ground, and the dry ingredients also include sugar and salt.  The starter is formed as scalded milk is poured over the dry ingredients, and then left to incubate for about twelve hours at 100 or so degrees.  Despite its name, salt is a relatively minor ingredient in the bread. 

The Van de Kamp’s bakery had a rich history which straddled my own childhood and years living in the greater Los Angeles area.  Although the bakery was originally sold by the Van de Kamp family back in the 1950’s when Theodore Van de Kamp died, the Dutch windmill style bakeries and fresh salt-rising bread remained a warm memory for many of us Southern California children.  When accompanying my mom to buy our bread, I was treated on more than one occasion to a free windmill toy and a cookie. 

By the mid-1970’s, the Van de Kamp bakeries had stopped baking the salt-rising bread I grew up on, but by that point I had left Southern California and moved up to the Bay Area, a region where the Van de Kamp bread had been seldom offered and shortly went out of business.  However, in San Francisco, sourdough bread reigned supreme and had since the California Gold Rush.

Sourdough bread also uses natural microbes as a rising agent, but the longer fermentation of the starter allows the Lactic Acid produced by the Lactobacillus to give the bread a uniquely sour taste.  Naturally occurring yeasts such as Saccharomyces exigua and Saccharomyces cerevisiae also participate in the rising.  Sourdough yeasts work slower than today’s packaged yeasts, increasing the time needed for fermentation to multiple days.  San Francisco sourdoughs are usually kept closer to 70 degrees and often need a week to become stabilized.

Flour and water are combined in the starter, and various methods for introducing micro-organisms and stabilizing the dough are used.  Often times, boiled potatoes are used to help increase the activity of the bacteria.  Creating a sourdough starter is a baker’s science, and each recipe is unique and starter closely monitored.  As a result, bakers are often using “mother dough” that is many years old.  Some bakeries, such as the Boudin Bakery, are able to trace their “mother dough” back to the Gold Rush era. 

During the 1980’s, as modern food processes and general business consolidation trended, San Francisco bakeries fell into the hardship of competition with prepackaged bread.  Smaller bakeries were driven out of business, and the long-term survivors tended to be the larger bakeries with well-established distribution channels.  I moved to Oregon during this time, and my observations upon returning to the Bay Area some years later made it clear that there was a stark change in the availability of good local sourdough bread.  Fortunately for my family, Judy was at the peak of her baking heyday during this time and we were seldom lacking in good bread around my house!

Fast forward to now, and the artisan bread movement has brought back the ability to purchase good, hand-made loaves of bread.  Specialty bakeries have been started and thrive in high numbers.  Even restaurants and grocery stores are taking the time to bake their own bread.  I personally continue to feel that no sourdough of modern San Francisco origin can compete to the distinct sour taste and texture of earlier days, but there is no Pickering starter dough dating back to 1970 lurking in my refrigerator, so I make do with what’s available.  It is my sincere hope that the continued evolution of artisan bread, gastronomy, and the souring culture will ultimately recreate my ideal sourdough again soon. 

Until then, at least we can look forward to St. Patrick’s Day each year, when Judy will rise to the occasion and bake a unique bread to treat us all again!


Replacing the Over-pressure Relief Valve Cartridge

Cleaning and Reassembly of the Over-pressure Relief Valve

  1. Remove the tubing connections to the Mixing Manifold. Use a 3/32” hex driver to remove the 2 screws holding the Mixing Manifold to the chassis. Use a 3/8” wrench to remove the end cap and discard the old Over-pressure Relief Valve Cartridge. Ultrasonicate the Mixing Manifold for at least 30 minutes. Rinse well with DI water.
  2. Connect the outlet of your HPLC pump to the Mixing Manifold inlet and pump 100% water at 0.5mL/min to verify the Mixing Manifold is not clogged. If the Mixing Manifold is still clogged after cleaning in an ultrasonicating bath, replace the Mixing Manifold Assembly (PN 1452-0040).
  3. Turn off the HPLC flow and make sure there is no pressure on the Mixing Manifold. Insert the new OPRV cartridge, green side down, and screw on the end cap to 20”lbs of torque. To approximate this level of torque, first finger tighten, then tighten an additional 1/8-1/4 turn with a 3/8” wrench.
  4. To verify the opening pressure of the Over-pressure Relief Valve, plug the two side inlets of the Mixing Manifold and turn on the HPLC pump to 0.5mL/min. Allow the pressure to slowly rise. The Over-pressure Relief Valve should open around 485psi. If the opening pressure is too low, tighten an additional 1/8 of a turn with a 3/8” wrench.

David Mazawa
Technical Support Chemist
Pickering Laboratories, Inc.
1280 Space Park Way
Mountain View, CA 94043 USA
Phone: (650)694-6700 ext. 710
Fax: (650)968-0749


AOAC Mid-year Meeting, SPIFAN and Tea

AOACAOAC’s 5th Annual Mid-Year Meeting was held in Gaithersburg, Maryland March 16-20. Stakeholders panels, Working groups and Expert Review panels were working on developing consensus standards, evaluating and recommending the methods as well as identifying and prioritizing issues and needs in areas of Infant and Adult nutrition, food and produce safety and Dietary supplements.  

Maria Ofitserova attended the meeting of Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) where wide range of topics was discussed.  The Panel was updated on the state of methods to identify the Whey Protein content in formulas via amino acids analysis and approved Standard Method Performance Requirements (SMPRs) for Vitamins B1, B2, B3 and B6. There was a discussion about the urgent need for methods to determine Sodium Monofluoroacetate (Compound 1080) in response to threats to adulterate baby formula in New Zealand. Sodium Monofluoroacetate is used to control rodents, foxes, rabbits and other animals in Australia and New Zealand and is very toxic. The panel was able to review and approve three fit-for–purpose methods for analysis of Compound 1080. The Panel was also presented with information about harmonization of standards and methods to ensure safety and quality of infant and adult nutritional products and cooperation of AOAC with other organizations responsible for developing International Standards and Guidelines, such as CODEX and ISO.

The full-day session of SPIFAN Expert Review Panel (ERP) was dedicated to reviewing methods seeking to obtain the status of AOAC either First Action or Final Action Official Method.

AOAC Stakeholder Panel on Dietary Supplements (SPDS) launched three new working groups that will be developing Standard Method Performance Requirements for analysis of Aloin in Aloe, Vitamin D in supplements, premixes and raw materials and analysis of different components of tea, including catechins, theaflavins, and special amino acid Theanine.  Pickering is especially excited about being part of the Tea working group since we have developed an easy and robust method of analysis for Theanine and tea using cation-exchange column and post-column derivatization with Trione, Ninhydrin reagent.

Pickering Laboratories will continue working with AOAC groups to keep track of important issues in Food analysis and focus our R&D efforts.


Sweat, a History of and New Products Coming

sweatThe Evolution of Artificial Perspiration, Pickering-Style
By Rebecca Smith

Our employees’ favorite response to the standard “what do you do?” question plays into the novelty of some of our lesser known products:  “We make artificial sweat!” 

Coming from a traditional chromatography background (with over 30 years of reputation as the “post-column people”), it has always been a fun conversation starter, not to mention a great way to illustrate exactly how unique Pickering Labs is. 

Pickering was initially approached by the forensics industry.  Our first sweat customer, Crime Sciences Inc., inquired into the possibility of an artificial perspiration solution that would mimic a human fingerprint.  The goal was to provide a control for the fingerprinting tests used by forensic investigators.   Intrigued by the possibilities, Michael Pickering jumped on the opportunity. He began researching the chemical composition of actual human eccrine sweat.  As a result, our artificial perspiration is the only formulation standardized to be used across all industries as it mimics true human sweat and does not rely on any one desired testing result. 

After adding artificial perspiration to our catalog, we spent several years selling a bottle here and there.  Other than the catalog and webpage, we weren’t really focusing in on ‘sweat’ as a product line.  Beginning in 2011, our sweat sales unexpectedly began to take off.  We also started getting an increased number of inquiries for industry-specific artificial perspirations, with specific components designed to test one particular trait of the product.  It appeared that the time had come to expand our sweat offerings!

Today, we offer about ten different formulations of artificial perspiration (in addition to five artificial saliva formulations and three urines).  We make numerous proprietary custom formulations for our customers as well.  We have also expanded our offerings to include the ability to modify the pH or stabilization of any sweat formulation to suit specific needs a customer might have. 

Pickering continues to see increasing sales of our very popular artificial eccrine perspiration.  To accommodate growing use and facilitate larger orders, we have even begun selling our stabilized eccrine perspiration in larger bottles!  Now a customer can choose the best fit for them – 5mL, 200mL (most popular), and now 950mL. 

The unique qualities of Pickering Labs that make us so responsive to customer needs continue to thrive.  And now with our expanded product testing offerings, we are starting to be known not just as the “post-column people,” but also be recognized as “those people that make sweat” too!

It’s been a fun ride so far.  And our primary source of advertising continues to be word of mouth, so feel free to bring us up the next time you’re looking for a conversation starter!

Pittcon 2015

Pittcon photoNew Orleans, 2015 Pittcon Exhibition –  919 exhibitors, 1,690 booths and an estimated 18,000 attendees. Pickering laboratories exhibited to share the latest products and technologies with customers, distributors and partners. There was a lot of attention to this year’s big introduction, the DEXTech Sample Clean-up system for PCBs and Dioxin. Designed to be faster, cleaner and better automated than industry standard processes the DEXTech provides Dioxin and PCB sample Clean-up at significantly lower price per run while also being faster and safer.

The Freestyle automated sample clean-up workstation highlighted the ThermElute system for Aflatoxin sample-Clean up that has a direct connection to the HPLC. Not only are the innovative Aflatoxin immunoaffinity SMART columns economical but they are incredibly fast. Now you can automate the sample clean-up and include the analysis in one setup.

One of the growth areas in the Pittcon show was the growing focus on Food Safety. Pickering laboratories continue to develop applications that focus on food safety and authentication with new methods introduced at Pittcon:

The surprise to many long time Pickering Labs customers is the introduction of the Product Test Solution line of artificial perspiration, saliva and urine. The long history with Post-Column derivatization products continues with the additional product expansion into sample clean-up products and now the products for the Product Testing laboratory market. These products build on our expertise in Amino Acid Analysis and chromatographic grade reagent manufacturing capability. Each product is manufactured in precise compliance with product testing protocols from NIST, ATSM, AATCC and numerous other standards organizations. The reliability and reproducibility of all Pickering Laboratories products is now available to the Product Testing laboratory market.

AHPA User Meeting

AHPHThe 35th annual Natural Products Expo West, the world's largest natural, organic and healthy products event, took place March 4 – 8 at the Anaheim Convention Center in California. The American Herbal Products Association (AHPA), the national trade association that is focused primarily on herbs and botanicals and herbal products, held its annual member meeting and the various committees meeting during this event. This year's meeting featured a keynote speech by Josephine P. Briggs, M.D., Director of the National Center for Complementary and Integrative Health (NCCIH) at the National Institutes of Health (NIH). Her speech focused on research in the diverse medical and health care systems, practices and products that are not generally considered part of conventional medicine. The committee meetings discussed issues that are impacting herbal products industry

Chromatography Quiz #19

Chromatography Quiz #18 Results

We would like to congratulate our grand prize winners of our last newsletter’s puzzle quiz: Helene Lachance from Shur-Gain Nutreco, Tom Schneider from Suffolk County Water Authority, Narjes Ghafoori from LA County Environmental Toxicology Lab, and Joy Gottlieb from New Mexico Department of Health Scientific Lab Division!

q19-1They have each won and will shortly be receiving:
a Polaroid Cube Action Flash Memory Digital Camcorder
(POLC3X) with HD-1080p from!!

We would like to thank all of you for your submissions!

The correct answer (click to enlarge):


Thank you!
Pickering Labs

Chromatography Quiz #19: Glyphosate Analysis High Pressure Troubleshooting!

Answer the three high pressure questions correctly and win a prize! Simply email your answer as well as your full contact information to Rebecca at by May 15th, 2015 in order to win. You will receive email confirmation that your submission has been received. The answer to the puzzle and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission).

Glyphosate Analysis for US EPA Method 547

HPLC running with Pinnacle PCX dual-pump system. Assume normal operating conditions (with respect to flow rates, temperatures, etc.).

Glyphosate Analysis normal pressures

Column Pressure Reagent 1 Pressure Reagent 2 Pressure
90 bar 230 psi 130 psi

After a month of analysis your pressures have changed. What is the most likely cause of the problem in each of the three scenarios below?

Scenario One:

Column Pressure Reagent 1 Pressure Reagent 2 Pressure
100 bar 430 psi 330 psi
  1. Pre-column GARD blocked
  2. Heated Reactor obstructed
  3. Ambient Reactor obstructed

Scenario Two:

Column Pressure Reagent 1 Pressure Reagent 2 Pressure
100 bar 430 psi 430 psi
  1.  Pre-column GARD blocked
  2. Heated Reactor obstructed
  3. Ambient Reactor obstructed

Scenario Three:

Column Pressure Reagent 1 Pressure Reagent 2 Pressure
180 bar 230 psi 130 psi
  1. Pre-column GARD blocked
  2. Heated Reactor obstructed
  3. Ambient Reactor obstructed

An Interview with Laszlo Torma

By Wendy Rasmussen

With Laszlo retiring on December 12th, I thought it would be fun to do a short interview with him to learn a bit about his experiences and his plans for retirement. We have all really enjoyed working with him over the years and even though we’re a little sad to a friend leave the company, we’re also very happy and excited that Laszlo and his wife Sondra can enjoy all the wonderful things about living in Montana –skiing, viewing wolves in Yellowstone National Park, and delicious steak dinners all come to mind…

Laszlo Torma enjoys the sights and sounds of "Venice"

Laszlo officially joined Pickering in July of 2002 as Director of Technical Relations, but we knew him even before then. He worked at the Montana Department of Agriculture for 35 years (from 1965-2000), where he was one of Pickering’s best customers. I remember meeting Laszlo for the first time at a Midwest AOAC meeting in 2000. Very soon after I came to admire his love and respect for the science and the people.  I have learned a great deal from him over the years.

WR: What do you look forward to most in retirement?
LT: Relaxing and trying to learn more about computers. Hopefully still be able to go skiing


WR: How did you get started in science?
LT: My uncle was a veterinarian who enjoyed toxicology. Whenever I had a chance (that is, not going to soccer camp or playing) I was around him, “helping” him. He directed me toward the sciences like toxicology and chemistry.

WR: Favorite city/state/location to travel
LT: I have to be selfish and say Budapest (laughing)  But in the US, New Orleans is always fun

WR: What was the most unusual test/sample/situation in the lab?
LT: Stomach contents.  And sometimes we received Grizzly bear saliva to test. It was part of a forensic case to determine whether the bear had been poisoned with strychnine. Some of the bears had indeed been poisoned.

WR: What are one or two of your accomplishments which you are most proud of?
LT: At the time when I joined Pickering, somebody had started false rumors about the company which were saying that we were closing shop; successfully put that to rest. I worked hard to put Pickering “back on the map”.  Also, the activities with AOAC, the state Ag labs, and also EPA & FDA activities. Of our activities with AOAC, I am especially proud of our Award for our Single Laboratory Validation of the Year (for Multi-Residue Mycotoxin analysis). We worked very hard on that.DSC_7505

WR: How did you meet Michael Pickering and how did you become a Pickering customer?
LT: I met Michael at one of the Midwest AOAC Meetings in the late 1990s. Laszlo_Michael_MWAOAC
Nancy Thiex, who was with South Dakota State University at the time, introduced me to him. We had a homemade Post Column derivatization system which was large and cumbersome. After talking with Michael, we decided to purchase Pickering systems for carbamates and amino acid analysis.

WR: What is your fondest memory of working with Pickering Labs?
LT: Working with all of you. Overall we had a very good relationship and I enjoyed working with most of the peopleMINOLTA DIGITAL CAMERA

WR: Who will keep us company at the Tiki Hut in Florida?
LT: (Laughs) You carry that torch very well. Just think of me when you’re there

Even though officially Laszlo has retired, he promises to keep in touch between ski runs.  Feel free to contact him directly until January 10, 2015. His email is

Wendy, Maria, Mike, David, Saji, and Rebecca are committed to carry on Laszlo’s good work and will continue to stay active at the meetings within the analytical chemistry community.  We certainly have some very big shoes to fill!

Here’s to a very happy, long and healthy retirement for Laszlo!

All the best,
You can also contact me with any questions:


Pass the Bubbly

By Michael Pickering

I first had the pleasure of knowing Laszlo through our mutual involvement with AOAC (far longer ago than I’m willing to admit).  I admired his technical knowledge, and the excellent ways in which he represented the interests of his home state of Montana, his lab there, and the AOAC organization as a whole.

Laszlo first started working for Pickering Labs twelve years ago, and my professional admiration for him blossomed into a lasting friendship.  My wife and I have many fond memories of visiting Napa and Yellowstone with Laszlo and his wife Sondra, and over the years we have had the pleasure of hosting them several delightful times in our home.

Laszlo has been a valuable member of our team here at Pickering, too.  His insight is bubblyunmatched, and we have benefited so much from his tireless travel on our behalf.  I have always known that Pickering Labs is well represented by Laszlo, and I particularly enjoyed traveling with him to AOAC International 2009 in Philadelphia and watching him work firsthand.

So, I propose a toast to Laszlo Torma!  Congratulations on your retirement!  You will be greatly missed, and thank you for your hard work and warm friendship.


The Pickering team raise a glass to Lazlo on Friday, December 12, 2014:

Champagne for Laszlo(L to R): Jim, Wendy, Fidel, Sareeta, Mike, Michael, Ed, Tony, Anita, Maria, Gloria, Rebecca, Diana, Gabriela, Severo, Jay, Saji, and David (behind the camera)

Simultaneous Analysis of B Vitamins in Protein Powders and Supplements

Our New Method Abstract, MA 239, describes the Simultaneous Analysis of Vitamins B1, B2, B3, and B6 using post-column derivatization.

B vitamins are a group of water soluble vitamins that play an important role in cell metabolism. This group consists of a number of compounds including Thiamine (Vitamin B1), Riboflavin (Vitamin B2), Niacin and Nicotinamide (Vitamin B3) and Pyridoxine and Pyridoxal (Vitamin B6). B vitamins are found in plant and animal food sources, such as legumes, nuts, green leafy vegetables, red meat and poultry. Many commercial food products are fortified with vitamin B complex and people could take multi-vitamins supplements to help fight vitamin B deficiencies.

Pickering Laboratories offers a method for simultaneous determination of Vitamins B1, B2, B3 and B6 in supplements and protein powders. The method uses chemical and photochemical post-column derivatization with Fluorescence detection that increases sensitivity and selectivity of analysis. Photochemical derivatization required for Niacin and Nicotinamide and chemical derivatization is needed for Thiamine. Vitamins B2 and B6 have natural fluorescence.Mixed B Vitamins Chromatograms

METHOD Overview. (to download the complete Method Abstract click HERE)
Instrument set up

Connect the instruments in the following order:
– Pinnacle PCX post-column derivatization instrument
– UVE™ photochemical reactor
– Fluorescence detector

Sample Preparation
For protein powders:
To 0.5 g of samples add 50 mL of extraction buffer (0.1 N NaOH adjusted to pH 2 with Phosphoric acid). Homogenize using hand held homogenizer for 30 sec and heat on a water bath at 100 ºC for 30 min. Cool the solution down, filter through 0.45 um nylon filter and inject. Protect from light.

For multi-vitamins supplements tablets:
Blend at least 10 tablets to a fine powder and mix the entire sample thoroughly. Weigh 250 mg of sample and add 90 mL of DI water acidified to pH 2.6 with 0.1 N HCl. Stir using magnetic stirring plate for 2 hours, protecting from light. Make the volume up to 100 mL with acidified water. Filter the sample through a 0.45 um nylon filter and inject. Protect from light.

Analytical Conditions
Analytical Column: Thermo Hypersil, Aquasil C18 (4.6×150 mm)
Column Temperature: 40 ºC
Flow Rate: 1 mL/min
Mobile Phase:
Solvent A: Potassium Phosphate Monobasic in DI water, adjusted with KOH, brought to 1L DI water.
Solvent B: Acetonitrile.

Post-column Conditions
Post-column Derivatization System: Pinnacle PCX and UVE Photochemical Reactor
Reactor Volume: 0.5 mL
Reactor Temperature: 30 ºC
Reagent: Sodium Hydroxide in DI water, with Sodium Sulfite
Detection: FLD