Category Archives: AOAC

Amino Acid Analysis, AOAC, china, Ninhydrin, pickering laboratories, pinnacle pcx, post-column derivatization, Trione, Whey proteing

Calculation of Whey Protein Fraction in Milk-Based Infant Formula

A method for the calculation of whey protein fraction in milk-based formula products was developed and validated by a group of researchers from Abbott Nutrition, Covance Laboratories and AOAC International. The method is based on calculating the ratio of (Asx + Ala)/(Pro+Phe) determined from the amino acid profile of the hydrolyzed sample.

The method was approved as AOAC Official First Action Method 2012.07 and is appropriate for accessing compliance with whey content requirements of GB 10765-2010 (National Food Safety Standard Infant Formula)*. It is applicable to finished products containing both intact and partially hydrolyzed whey proteins.

According to this method, the Amino Acid Profile of hydrolyzed samples is determined using cation-exchange chromatography with post-column derivatization and UV/Vis detection. The researchers used Pickering Laboratories post-column derivatization system, our patented Trione Ninhydrin reagent and Pickering Sodium analytical column and buffers.

The method performance was evaluated using non-fat dry milk and products with whey levels from 32% to 63%, including NIST Infant Formula Standard Reference Material. The repeatability ranged between 0.3 and 2.5 %, while intermediate precision were between 2.6 and 3.4%. Average recoveries ranged from 97 to 100%.

The unmatched accuracy and precision of amino acid analysis by HPLC with post-column derivatization allowed the researches to develop a robust mathematical model for calculating whey protein fraction that can be successfully applied to a wide range of products. This proved once again that post-column derivatization analysis of amino acids is still a method of choice for laboratories that require highly accurate results.

Pickering Laboratories offers a total solution for amino acids analysis, including post-column derivatization systems, reagents, columns, buffers and standards.

The reference to the published study is below. The First Action Official Method 2012.07 can also be found online at http://www.eoma.aoac.org/.

Calculation of Whey Protein Fraction in Milk-Based Infant Formula: First Action 2012.07

Authors: Wesley Jacobs, Paul Johns, Phillip Haselberger, Joseph J. Thompson, Darryl Sullivan, Steve Baugh.

Source: Journal of AOAC International, Volume 96, No. 3, 2013, pp. 502-507

 

(*) this is a Chinese Standard

AOAC, HPLC, pickering laboratories, pinnacle pcx, post-column derivatization

Polyether Antibiotics in Animal Feed

Our updated Method Abstract 264 describes the analysis of Monensin, Salinomycin, Narasin, & Lasalocid in Animal Feeds.

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 [1, 2].

Post-column derivatization of Polyether Antibiotics is done using highly acidic Vanillin or DMAB reagents. The Pinnacle 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.

Chromatograms of Polyether AntibioticsMETHOD
Sample Preparation
To 25 g of finely ground feed sample, add 100 mL of extraction solution (90% Methanol – 10% water). Shake for 1 hour at high speed using a mechanical shaker. Let the solids settle and filter an aliquot of the extract for injection. Dilute with extraction solution if needed to fit the calibration curve. Use a 2.5 g portion when testing premixes.

Analytical conditions
Analytical Column: Polyether Column, C18, 4.6 x 250 mm, Catalog No 2381750
Temperature: 40 ºC
Flow Rate: 0.7 mL/min
Mobile Phase: 90% Methanol, 10% of 5% Acetic Acid solution in water, isocratic
Injection volume: 20 μL

Post-Column Conditions
Post-column System: Pinnacle PCX
Reactor Volume: 1.4 mL
Reactor Temperature: 90 °C
Reagent 1: Concentrated Sulfuric acid / Methanol (4:96 v/v)
Reagent 2: 60 g of Vanillin in 950 mL of Methanol
Reagent Flow Rate: 0.3 mL/min
Detection: UV/VIS 570 nm (for Lasalocid – FLD, Ex. 322 nm, Em. 370 nm)

Conclusion
Analysis of Polyether Antibiotics by HPLC with Post-column derivatization is a robust and sensitive method that utilizes standard equipment and could easily be adopted by testing laboratories. It allows for testing of different ionophores at wide range of concentrations,
including at trace levels. Using Pinnacle PCX post-column derivatization system, factory configured for the analysis, guarantees stable and reproducible results.

The full application note as well as our complete Product Catalog can be downloaded from our website: www.pickeringlabs.com

table for polyether antibiotics

AcceCLEAN, aflatoxin, amino acid, Amino Acid Analysis, amino acids, antioxidants, AOAC, AOAC's Laboratory of the Year Award, artificial perspiration, carbamate, Chromatography, clean-up, column, deoxynivalenol, detector, dietary supplements, DON, Dr. Pickering, elisa, eluvac, ergot alkaloid, freestyle, GARD, glyphosate, GPC, Guard, HPLC, immunoaffinity cleanup, Multi-residue Mycotoxin Analysis, mycotoxin, natural toxins, New Products, Ninhydrin, ochratoxin, paralytic shellfish toxin, Physiological Fluids, pickering laboratories, pinnacle, pinnacle pcx, Post-column, post-column derivatization, psp, sweat, syringe pump, Trione, UVE, vector

Pickering Laboratories in 2013

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By Wendy Rasmussen

In recent years, we have released several new products and applications, and with still more on the horizon, it occurred to me that now would be a great time to summarize the Pickering of today – our mindset and our wide variety of products & applications.

Acai Berries
Acai Berries

No longer are we simply the “Post-Column Company”. We are the “Automated-Sample Antioxidants” company.  Think of us as the new “super fruit.” The Acai berry, or perhaps the new Chia Seeds (incidentally, we do have a post-column application for the identification & quantitation of  Antioxidants in a variety of matrices).

We are still very active, and we as a company plan to be here for many years to come. We are still the company founded on chemistry and a desire to to teach, to spread our technical expertise, to support our customers.

It’s been a few years now since Pickering began distributing and supporting our LCTech Product line.  The products have shown an ever increasing interest here in the US and in Canada (our official Sales Territory for this product line). We are very proud to offer these products and we hope we can develop it further in the future.

Historically, we have provided the back-end of an analysis (post-column derivatization). Nowadays, we can provide the front-end of analysis as well (the sample-cleanup).

In thinking about our product offerings, I realized that a simple list does not effectively show the scope of the products we have to offer in 2013 – primarily because we have a lot of overlap between products and product lines.  We’re not a vertical company in that regard.  I suppose one could say our product offerings are more circular in that many do not fall into a single distinct category.  I am a very visual person, and for me, a Venn diagram and our overall “product scale” really helped to understand and clarify our products:

Venn Diagram of Pickering Laboratories
Venn Diagram of Pickering Laboratories
General "Product Scale" for Pickering Offerings
General “Product Scale” for Pickering Offerings
For those of who like lists, you can find one Here, on Pickering’s website, and on LCTech’s Website

For any Questions, please feel free to contact us:

Pickering Laboratories, Inc.
Mountain View, California
Email: sales@pickeringlabs.com
Phone: (direct) 650-694-6700 or (toll-free) 800-654-3330

 

Image of Acai Berries:  http://acaiberryeducation.com/

aflatoxin, AOAC, clean-up, eluvac, freestyle, immunoaffinity cleanup, mycotoxin, pinnacle pcx, post-column derivatization, UVE

Aflatoxins in Edible Oils Collaborative Study Published

Pickering Laboratories, Inc was one of several laboratories who participated in a collaborative study, the results of which were published in the November-December issue of Journal Of AOAC International.

Here is the reference:

Determination of Aflatoxins B1, B2, G1, and G2 in Olive Oil, Peanut Oil, and Sesame Oil using Immunoaffinity Column Cleanup, Post Column Derivatization and Liquid Chromatography/Fluorescence Detection: Collaborative Study.

Authors: Bao, Lei; Liang, Chengzhu; Trucksess, Mary W.; Xu, Yanli; Lv, Ning; Wu, Zhenxing; Jing, Ping; Fry, Fred S.

Source: Journal of AOAC International, Volume 95, Number 6, November-December 2012, pp. 1689-1700(12)

Participating laboratories could use Photochemical Derivatization or electrochemical derivatization.  The sample clean-up was performed using Immunoaffinity clean-up columns.

Pickering has many great tools for the analysis of Aflatoxins, including the UVE Photochemical Reactor, our Pinnacle PCX, immunoaffinity clean-up columns, HPLC columns, and column handling equipment such as the FREESTYLE SPE, AcceCLEAN, and EluVac.

antioxidants, AOAC, herbal products, mycotoxin, natural products, natural toxins, pickering laboratories, supplyside

Pickering exhibits in Las Vegas

-By Mike Gottschalk

Las Vegas, Nevada – Oct. 1 – 5 was the site of the AOAC international show this year.  Pickering Laboratories participated as usual in this important International event. “We see many of our customers and distributors from all over the world at this show” said Wendy Rasmussen, sales manager Pickering Laboratories. “We get to show our new products and catch up with them with new developments in their business.”

Pickering Laboratories presented Posters of our new applications Chrome VI and Antioxidants in foods. The herbal supplement market is a growing market and with FDA guidance, more concerned with testing for quality in their products. “We continue to develop methods in matrices important to this market including the antioxidants, Aflatoxins, Amino Acids and others”  said Laszlo Torma, technical liaison for Pickering Laboratories.

The AOAC international show enables laboratories and suppliers to be involved in the mission of creating analytical methods for today’s most pressing testing challenges. Pickering Laboratories is an award winning member of several committees and laboratory collaborations to further the goal of analytical excellence.

Las Vegas, Nevada – Nov. 6-9 – Yes! Las Vegas Again! This time for the annual Supply Side West show.  1,800 vendors and 30,000 participants meet to network and explore resources in this, the largest gathering of Herbal supplement suppliers and vendors.  Now that the FDA enforcements are increasing, many Herbal supplement manufacturers are working hard to improve their analytical testing capabilities and Pickering Laboratories is there to help.  “With several methods for herbal supplement testing and extensive experience in the food safety industry we can offer experience and laboratory equipment support to the herbal supplement manufactures” – said Mike Gottschalk, VP Marketing, Pickering Laboratories.

Laszlo Torma enjoys the sights and sounds of “Venice”

Pickering Laboratories is a member of the “American Herbal Products Association” and member of the Laboratories Methods Committee for AHPA. The collaboration with AHPA and the Supply Side West show have provided valuable insight to the needs of the Supplement community and the unique capabilities Pickering Laboratories can offer this market.

Amino Acid Analysis, AOAC, Ninhydrin

Midwest AOAC Meeting

This year’s Midwest AOAC meeting was held in St. Louis, Missouri from June 4-6. 
It was well-attended with a good technical program.

Gateway Arch in St. Louis, MO*

At this year’s meeting we hosted an Amino Acid workshop, in which attendees learned tips and troubleshooting techniques for amino acid analysis. All analytical methods were covered, including some discussions on sample preparation for amino acids.

The post-column analysis of amino acids is a tried and true technique. By derivatizing the amino acids post-column, any matrix components which might otherwise interfere with the derivatization steps are eliminated, leaving only the amino acids to react with the reagents. This leads to exceptional reproducibility, sensitivity and ruggedness.

Our Pinnacle PCX instrument is especially suited to amino acid analysis with its heated column oven (to perform temperature gradients), and pulse-free syringe pumps. More information can be found on our website: www.pickeringlabs.com, or by downloading one of the following:
MA380:  30-Minute Amino Acid Analysis of Hydrolyzed Samples
or our Amino Acid Brochure
View of St. Louis from the top of the Arch

* Interesting Fact: Gateway Arch is part of the Jefferson National Expansion Memorial. It was designed in 1947, but construction did not begin until 1965.  It opened to the public in 1967. http://en.wikipedia.org/wiki/Gateway_Arch

AOAC, natural toxins, paralytic shellfish toxin

AOAC Pacific Northwest Section 2012

Marine and Freshwater Toxins Analysis Third Joint Symposium and AOAC Task Force Meeting
University of Puget Sound, Tacoma WA
June 18-22, 2012
The AOAC Pacific Northwest Section (link: http://www.aoacpacnw.com) annual meeting in Tacoma WA has just concluded. The meeting was full of informative oral presentations and posters ranging from natural disasters to algal blooms due to climate change. One recurring theme is the push to move away from the Mouse Bio-assay (MBA) for shellfish toxin testing. Recently there have been a few AOAC approved methods for toxin testing that do not involve injecting mice. A few oral presentations were updates on the success many labs are having in moving to these chemical methods and reducing the usage of the MBA. One of the successful approved methods is the Post-column Oxidation method for Paralytic Shellfish Toxins (link to PSP method abstract). Both the Pinnacle PCX and the Vector PCX (link to PCX brochure) post-column instruments have been used for this analysis. 
Pickering Laboratories was proud to sponsor the AOAC PNW annual meeting. We presented two posters at this year’s meeting. Please download them from the links and contact support@pickeringlabs.com with any questions.
Method Abstract 103.5: Paralytic Shellfish Toxins
Method Abstract 102: Analysis of Biogenic Amines
Mt. Rainier