Pickering Laboratories
Menu
 
Menu

Chance Favors the Prepared Mind

“Chance Favors the Prepared Mind” – Louis Pasteur
by Michael Pickering 
Chapter One: Preparation
My father and his four brothers were auto/diesel mechanics.  All the families, including grandma and grandpa, moved to Moorpark, CA during World War II. It’s a small agricultural suburb east of Ventura. Small in this context means few paved roads.  The move occurred when I was about two years old.  Probably just after my brother, who was 23 months younger than me, was born.  
They obtained a property on US Highway 101 in Ventura.  The site had three commercial venues: the “Red Ball Café,” a gas station, and a multi-bay garage with a hydraulic lift.  The men managed the auto business and the women saw to the restaurant.  Grandpa was the gofer and I was his shotgun.  Anyone alive today who ate at the Red Ball during that time will have more than one fond memory. 
By the time I was five, properly greasing a wheel bearing and installing it was something I knew how to do by feel, and how to set the cotter pin.  What I learned is that it is extremelyimportant to expel ALL the air pockets before installation.  It didn’t make any sense to me then, but what five year old is going to doubt a team of mechanics.  Moreover, his father and uncles.  Now that I’m the mechanic, I get it: it’s a concept of Chaos Theory.  (See Figure X)
Figure X: A ball bearing from an improperly lubed auto front wheel.  The balls contact the tapered spindle on the inside (attached to the car) and a wheel race pressed into the drum.  All the balls from this wheel looked like this.  The outer race in the drum looked like a choppy sea, yet the spindle was unmarked.  The air bubbles and the ball orientation were maintained in perfect symmetry by chaos. 
Chapter Two: Chance
By the time I was in middle school, we lived in Highland Park, a small town on the first freeway on Earth – the Pasadena.  Freeways then didn’t have numbers; they were named for their termini (the Santa Anna, the San Bernardino, the Harbor, etc.).  We were the penultimate town before the freeway ended at a light signal in Pasadena at Orange Grove Blvd.  
The boulevard through Highland Park is the world famous Figueroa.  Town was about two miles from our neighborhood and a gradual rise most of the way to the movie theater. Since the movies changed once a week, that was our minimum number of journeys.  There were, however, more trips than that in the summer, because the public pool was further up Figueroa.  
Exiting the movies one day, someone, probably me, suggested that we have a coasting contest.  The rules were simple: one could peddle as much as possible to cross street A, about ¼ mile of the course, then not at all to the finish line at cross street B.  Joe McNeil won the first race, and I took second.  
Well, I decided that if I wanted to win, I’d have to beat Joe.  So I began to think of ways to create an advantage.  After all, we all had three speed (hub) bikes, called English racing bikes at the time. (See Figure Y)  When I realized the race was mostly coasting, I also knew the solution was to reduce friction.  Then I remembered hand packing wheel bearings, which is where I started the project.  I removed and replaced all the bearings, including the pedal hub.  Included in the soup-up job was the most expensive waterproof lube I could find.  It felt more like hand lotion than grease.  While I was preparing the bearings, my mind drifted to other ways to lower friction.  It came to me as an epiphany: any wobble of the wheels would cause friction on the bearings and on the road surface.  
Figure Y: A 1953 Schwinn three speed bicycle.
Although my only thoughts about spokes until then had been to keep clothing and body parts out of them, I had changed enough flat tires to know that they were attached to a threaded nut anchored on the OD side of the rim, and the spoke exit on the ID of the rim was a tension adjustment nut.  So it was back to the bike store to buy a new tool.
My first guess was to tune all the spokes to the same audio frequency.  Since I had no way of knowing the true frequency, my second guess was to pick the highest frequency or tightest spoke.  It also simplified the task to require only tightening.  A jig was prepared in the backyard with two 2 x 4’s so the wheels could be levelly mounted and spun.  The spokes were plucked to find the highest frequency, whereupon all spokes were tuned to match.  When done, the rim (as viewed rotating in the jig from a planar angle, perpendicular to the axle) was ‘S’ shaped.  So, Plan B was hatched. 
 
True flatness had to be established by reference to a fixed point.  Another stick with a horizontal nail through it as a palp or feeler was driven into the ground.  The spokes are anchored in turn on opposite sides of the rim.  As the rim turned, it drifted away or toward the feeler gauge.  So the process was: loosen one spoke, and tighten the next.  The eventual result was two true rims. 
Keeping my head down near the handle bar and centered over the quill, to lower friction even more, I never lost another race.

Chromatography Quiz #9

Chromatography Quiz #8 Results
We would like to congratulate the grand prize winners of our last newsletter’s Carbamates Analysis Chromatography Quiz: Mary Benzinger from North Coast Laboratories, and Keena Njoroge and Matthew Hartz from Underwriters Laboratories!!!
They have won, and will shortly be receiving: Wine Hourglasses courtesy of Uncommongoods.com! Additionally, all participants will be receiving a $20 gift card from Jamba Juice!  Again, we would like to thank all of you for your submissions.  

The correct answer for the modified Carbamates chromatogram: the noisy baseline is due to the HPLC pump having excessively large pulsations (or pressure variations).  Post-column systems containing reciprocating pumps can also cause noisy pulsations in the baseline, and the frequency of the sine waves should be evaluated to determine which pump is causing the noise.

This problem is most often caused by one of the following: bad pump seals, bad check valves, scratched or damaged pump pistons, faulty pulse dampener, or problems with connections to the pump. 

This problem can also be caused by dirty reagents or eluents, however in this case the pulsations would be accompanied by the elevation of the background signal. 

We had a lot of excellent responses to this quiz! 

Thank you! 
Pickering Labs

Chromatography Quiz #9:

Identify the error made when running the Amino Acids chromatogram below and win a prize!  Simply email your answer as well as your full contact information to Rebecca at rlsmith@pickeringlabs.comby May 15th in order to win.  You will receive email confirmation that your submission has been received.  The troubleshooting answer and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission). 

Amino Acid Analysis of Physiological Fluid

Pickering Standard: 1700-0180 Native Sample Standard, acidics and neutrals, in 0.1 N HCl, 2.5 µmole/mL, 10 µL injection

Pickering Column: 0354100T High Efficiency Lithium Cation-exchange Column, 4.0 x 100 mm

Normal Operating Conditions: (for reference only, condition changes may be reflected in chromatogram)
Column Temperature: 36 °C

Flow rate: 0.35 mL/min

Eluent Gradient:

TIME
Li275 %
Li750 %
RG003 %
0
100
0
0
12
100
0
0
48
65
35
0
90
0
100
0
95
0
100
0
120
0
94
6
122
0
94
6
122.1
100
0
0
140
100
0
0
Post-column conditions for amino acid analysis:
Reagent 1: Trione
Reactor 1: 130 °C, 0.5 mL
Reagent flow rate: 0.3 mL/min

Detection: UV-Vis Detector: 570 nm for primary amino acids,  440 nm for secondary amino acids
An example of a good chromatogram can be found here: Standard Lithium Chromatogram

Pickering Products

Mycotoxins: Clean-up Columns, ELISA Kits, Post-Column Derivatization Instruments & Methods, SPE manifolds (manual & automated) for the analysis of:

Aflatoxins
Ochratoxin A
DON
Nivalenol
Fumonisin FB1, FB2
Zearalenone
Ergot Alkaloids

Post-Column Derivatization: Pinnacle PCX, Vector PCX, UVE Photochemical Reactor, Columns, Reagents, Eluants for the analysis of:

Antioxidants
Mycotoxins (individual and multi-residue)
Amino Acids
Biogenic Amines
Paralytic Shellfish Toxin
Polyether Antibiotics
Hexavalent Chromium
Vitamins
Sugars
Nitrate/Nitrite
Bromate
Carbamate Pesticides
Glyphosate Herbicide
NDELA
Formaldehyde

Sample Preparation (clean-up) Instruments:

FREESTYLE for SPE, GPC, online-concentration
FREESTYLE ThermELUTE for Aflatoxin analysis (direct inject onto HPLC)
AcceCLEAN for SPE (incl. Immunoaffinity columns)
EluVAC vacuum manifold for SPE (incl. Immunoaffinity columns)
GPC QUATTRO for manual GPC Cleanup
DECS System for the cleanup of samples for Dioxin analysis

Chemistry Products:

Artificial Perspiration
Artificial Saliva
High Purity Water

Stand-Alone OEM Syringe Pump:

For any applications requiring an inert flow path, volumes up to 70mL, and pressures up to 500psi

For More Information visit:

www.pickeringlabs.com

or email: sales@pickeringlabs.com

Antioxidants Are No Accident

Recently we learned about a paper published by a team in Poland describing their work on the analysis of anti-oxidants. We wanted to share this work with the AHPA community.
Barbara Kusznierewicz and her colleagues from Gdansk University of Technology have developed a method to analyze antioxidants in complex mixtures by HPLC with post-column derivatization and UV/Vis detection. The authors studied three well-known reagents routinely used in colorimetric assays to measure antioxidant activity. They determined that Diammonium 2,2′-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and Folin-Ciocalteu reagent (FCR) were best suited for post-column derivatization of antioxidants after they were separated on reversed-phase HPLC column.
Photo from FoodProductDesign.com

Researches optimized HPLC conditions as well as post-column parameters such as concentration of post-column reagent, duration of derivatization reaction and reaction temperature. Trolox and 20 other phenolic compounds were investigated and scientists were able to demonstrate good correlation between Trolox equivalent antioxidant capacity (TEAC) determined by HPLC with post-column derivatization and standard colorimetic assay. This method was successfully applied to analysis of extracts from sloe fruits and mirabelle plums and allowed to calculate concentration of individual antioxidants as well as TE antioxidant capacity.


Pickering Laboratories strives to provide new post-column applications, and the instruments and chemistry to support these applications. It is our philosophy to provide a complete solution and customer support. We plan to follow-up this interesting research with some development of our own to see if we can optimize the post-column technique further. 
The full version of the paper can be found in the Wiley online library:
REFERENCE:
Kusznierewicz, B., Piasek, A., Bartoszek, A., Namiesnik, J., “The Optimisation of Analytical Parameters for Routine Profiling of Antioxidants in Complex Mixtures by HPLC Coupled Post-column Derivatization,” Phytochemical Analysis, 22, 392-402 (2011)

New! FREESTYLE Series Instrumentation

Pickering Laboratories introduced the Freestyle™ Sample Clean-up workstation from LCTech at this year’s AOAC International meeting in New Orleans.  Building on the success of the GPC Ultra product line of Gel Permeation Chromatography systems,  the FREESTYLE™Series  is an innovative design adding new time saving features to the automated sample clean-up work flow.

The Freestyle™ begins with:

  • FREESTYLE Basic, which has an XYZ robotic arm for automated liquid handling; dilutions, additions, mixing, extraction, dispensing, and other operations.
  • Add the GPC module for GPC processing of up to 4 GPC columns. 
  • Add to this the SPE module to enable SPE processing. 
  • Add the EVA module for programmable evaporation and solvent exchange for a completely automated in-line evaporation instrument.
Flexibility of the system starts with the suspended rack design. The system can handle multiple vial shapes from 1mL to 1000mL.

The FREESTYLE™software is drag and drop to program multiple sample parameters and able to handle exceptions to insert into the workflow. Graphical reporting and full audit logs round out the robust software.

The FREESTYLE™ automation of sample clean-up saves time, improves consistency and protects your staff from potentially harmful chemical exposure.

Send us an email or give us a call to find out how FREESTYLE™ can solve your sample clean-up challenges. 

Email: sales@pickeringlabs.com
Phone: Toll-free: 800-654-3330, Direct: 650-694-6700

Pickering Participates in BCEIA 2011 in Beijing, China

By David Mazawa
Beijing, outside of Exhibition Center
The Beijing Conference and Exhibition on Instrumental Analysis was held on October 12-15, 2011 at the Beijing Exhibition Center. This biennial exhibition is sponsored by the China Association for Instrumental Analysis and supported by the Ministry of Science and Technology of China. The BCEIA is 3 days long, because it will take you a full three days to cover all 17,000m² of exhibition space. 

The Beijing Exhibition Center became a bustling city of exhibitors and guests from all over the world showcasing instruments from the fields of Electron Microscopy & Material Sciences, Mass Spectrometry, Optical Spectroscopy, Chromatography, Magnetic Resonance, Electroanalytical Chemistry, Analytical Techniques in Life Science and Environmental Analysis.

BCEIA Exhibition Hall

David and Ameritech in Tianjin City
David and Tegent
I traveled to China to support our distributors that represented Pickering Laboratories at the BCEIA. I gave training to Ameritech in their Tianjin office and to Tegent in their Shanghai office. 
Both distributors have been working with Pickering Laboratories for many years and are completely capable of supporting our post-column instruments and applications. Their hospitality was incredible and I look forward to visiting them again in the near future.

 
Feel free to contact either Ameritech or Tegent for sale inquiries in China.


The Great Wall of China



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

Chromatography Quiz

Chromatography Quiz #7 Results
 

We would like to congratulate the grand prize winner of our last newsletter’s Amino Acid Analysis Chromatography Quiz: Jaime Lee Palmer from Underwriters Laboratories!!!

She has won, and will shortly be receiving: a gift card for Barnes and Noble!  Additionally, for this quiz all our participants will each be receiving a Smiley Face Sampler Box courtesy of The Popcorn Factory!  Again, we would like to thank all of you for your submissions. 
 
The correct answer for the modified Amino Acids chromatogram: the Trione reagent is oxidized.  Either the reagent has been improperly stored (not under Nitrogen), or has been in extended contact with air. 

Thank you! 
Pickering Labs

Chromatography Quiz #8:

Identify the error made when running the Carbamates chromatogram below and win a prize!  Simply email your answer as well as your full contact information to Rebecca at rlsmith@pickeringlabs.com by January 31st in order to win.  You will receive email confirmation that your submission has been received.  The troubleshooting answer and winner congratulations will be published in the next issue (to be anonymous, please notify Rebecca in submission). 

Carbamate Analysis for US EPA Method 531.1

Pickering Column: 1846250 Carbamate Column, C18, 4.6 x 250 mm

Sample: Actual customer’s 531.1 standard at 10ppb

Normal Operating Conditions: (for reference only, condition changes may be reflected in chromatogram)

Column Temperature: 42 °C

Flow rate: 1 mL/min

Eluant Gradient:
     

TIME
WATER
MeOH %
0
85
15
1
85
15
44
25
75
44.1
0
100
49
0
100
49.1
85
15
57
85
15

Post-column conditions:
Reagent 1: Hydrolysis reagent CB130 

Reagent 2: 100 mg of OPA, 2 g Thiofluor™ in 950 mL of CB910

Reactor 1: 100 °C, 0.5 mL 
Reactor 2: ambient. 0.1 mL
 

Reagent flow rates: 0.3 mL/min

Detection: Fluorometer  ex 330 nm,  em 465 nm

Full Chromatogram:

 





 

 Enlarged View:

 




 

Further Enlarged View:
  

For an example of a Good Carbamate Chromatogram, click here

Guaranteed Chemistry