September 30, 2021

CPG Exhibits at Mass Manufacturing Mash-Up


Research Scientist Veronica Holmes at CPG's table at the Massachusetts Manufacturing Mash-Up.

Cambridge Polymer Group is proud to have been an exhibitor at the first ever Massachusetts Manufacturing Mash-Up held on Tuesday, September 28, at Polar Park in Worcester, MA. The event attracted over 30 exhibitors and 600 attendees, including manufacturers, suppliers, academics and jobseekers.

Massachusetts offers a unique environment for manufacturing innovation. As the location of some of the world’s best universities, Massachusetts benefits both from the cutting-edge research conducted at these institutions as well as the talented graduates who often remain in state and start their own companies. Perhaps this high-caliber talent pool is why Massachusetts ranks third in the US for venture capital investment. The Mash-Up, organized by the Center for Advanced Manufacturing at MassTech (CAM), MassMEP, MassRobotics, FORGE, WPI, and MassHire, was designed to foster greater connections between these area resources of academia, business, and skilled workforce to solve industry challenges.

CPG helps manufacturers and startups by developing solutions to their materials problems, at all stages of their product development, production and distribution cycles. Our contract research experts determine what analysis or development a manufacturer requires. Working with CPG provides manufacturers with access to state-of-the-art instrumentation, skilled equipment operators, and materials experts who translate test results into solutions. Buying specialized equipment and hiring the staff for short-term research needs is prohibitively expensive for many manufacturers. CPG provides manufacturers with analysis or development that optimizes product and accelerates success.

CPG appreciated this opportunity to connect with our local manufacturing community in 2021, and we look forward to next year’s event!

Posted by CatherineCerasuolo
July 7, 2021

Forger Caught by Rheology of Biopolymer Gum Arabic

Gum arabic.jpg

Gum arabic, a sap harvested from acacia trees, is a very useful biopolymer due to its physical and chemical properties.

The forgeries and murders committed by Mark Hofmann in the 1980s have been dragged back into the cultural spotlight by a recent Netflix/BBC documentary. [1] Hofmann counterfeited an amazing breadth of documents supposedly written by American historical and literary figures such as George Washington, John Adams, John Quincy Adams, Daniel Boone, John Brown, Andrew Jackson, Mark Twain, Nathan Hale, John Hancock, Francis Scott Key, Abraham Lincoln, Emily Dickinson, Paul Revere, Myles Standish, and founding members of the LDS church. Hofmann’s forgeries fooled both the Library of Congress and the FBI, but eventually one of Mark’s associates began to suspect the authenticity of Mark’s finds. 

When it became obvious to Hofmann that his extensive forgery scheme was about to be exposed, he killed two people with pipe bombs in an attempt to hide his guilt. He then detonated a third bomb in his own car and appeared to be just another victim of a serial killer targeting document dealers. Public sympathy for Hofmann began to turn to suspicion when an eyewitness placed him at the scene of the first murder. Police raided Hofmann’s home but did not find what they considered to be proof of criminal activityIn reality, Hofmann’s house was filled with incriminating evidence, but it took the untiring efforts of two document examiners to look at that evidence in the right way, i.e., under a microscope. 

Catch You Later Alligator 

Despite an FBI lab’s determination that Hofmann’s documents were authentic, George Throckmorton, the document expert for Utah’s attorney general, and William Flynn, an Arizona document examiner, were skeptical of Hofmann’s “finds.” In most cases, previous authentication testing was limited to determining the age of the paper and/or ruling out the use of multiple inks. Because a forger may use a single ink and paper stolen from the blank pages of old books, Throckmorton and Flynn did not view the results of previous testing as conclusive. 

After inspecting numerous documents “found” by Hoffman under the microscope, Throckmorton noticed that the iron gallotannic ink was cracked. Throckmorton and Flynn were then able to confirm that all Hofmann documents contained the cracked ink, while genuine documents, also written with iron gallotannic ink but proven to be untouched by Hofmann, did not contain the “alligator” pattern. [2] 

Next, the dynamic document duo set out to demonstrate why the alligator patterned ink on Hoffman-handled documents was proof of forgery, and therefore a viable motive for murder. 

Accelerated Aging 

Flynn suspected that whatever method Hofmann used to make the document appear older had also cracked the ink. He treated iron gallotannic ink with sodium hydroxide, a common household product, and found that it was excellent at rapidly converting the iron in the ink to rust, reducing a process that usually takes years into days. However, even though the ink turned from black to a convincing deep brown with reddish tones, Flynn was not able to see the alligator cracks under the microscope.  
After conferring with Throckmorton, Flynn decided that his ink formulation might be different than Hofmann’s. He remembered seeing Great Forgers and Famous Fakes by Charles Hamilton in the property seized from Hofmann by police. Upon checking the book, Flynn stumbled upon a recipe for 19th century iron gallotannic ink that contained gum arabic, which was not present in Flynn’s first ink formulation. [3] 

Gum arabic (GA)the edible, hardened sap of acacia trees (Acacia senegal and Acacia seyal)is a hydrocolloid with an extensive list of accomplishments. Stone Age Sibudu Cave inhabitants used it to form the first super glue (a mixture of gum arabic and pigment that required heating at a specific temperature range, achieved by distance from the fire and wood selection). [4] Ancient Egyptians adhered mummy wrappings and mixed cosmetics and hieroglyph paints with it. 

In modern times, the biopolymer has continued to play a key role in art as a binder in paints, ceramic glazes, photography, and fireworks. GA is also a pervasive food and beverage additive, used as a stabilizer, emulsifier, thickening agent, binder and mouthfeel enhancerPharmaceutical applications include drug delivery and treatment of stomach inflammation. CPG appreciates gum arabic as reagent for volatile hydrocarbons testing in ASTM D460-91and aan ingredient in one of our favorite Valentine treats, candy hearts. But how did this ancient and incredibly useful material lead to the capture of the psychotic forger? 

Flynn synthesized Hamilton’s ink formula using gum arabic, penned his test script, then applied sodium hydroxide to the writing. When he put his sample under the microscope, Flynn did indeed find alligator patterned cracking. Exposure to sodium hydroxide causes a chemical change in the gum arabic, likely through the hydrolysis of the proteinaceous component of the gum arabic; the gum shifts from a thin fluid to a brittle material, hence the observed cracking.

The material evidence discovered by Throckmorton and Flynn was enough to convince the police that they now had motive. This perspective on the case opened many new fruitful areas of inquiry. Hofmann was the culprit, given away by gum arabicAlthough he was trying to recreate the original 19th century ink formulation by using the biopolymer, he would have likely remained undetected if he had omitted the telltale ingredient. 

Later during a confession in open court, Hofmann shared more details of his forgery techniques. He had constructed an ozone chamber out of a five-gallon fish tank, a piece of glass, some wire, and a jar filled with water and salt, and used it to simulate environmental damage to his forged documents. Hofmann also employed a vacuum to suck ink to the back side of a document to mimic seepage that usually occurs over the course of hundreds of years.  

What Would CPG Do? 

Integrity is one of CPG’s core values and we certainly do not perform accelerated aging for the purposes of forgery. We do provide both ASTM and customized accelerated aging to predict a material’s behavior over time, usually for medical device and industrial applications. Depending on your real-world applications, adjustments to standard testing are often necessary, and we have experience creating custom environments to mimic your product’s in-use conditions.  

CPG was founded in 1996so we were not around to help document gumshoes Throckmorton and Flynn find their telltale gumHowever, whave extensive experience in ink and paint analysis for manufacturers, including product deformulation and failure analysisContact CPG for your paints and coatings testing, R&D and product development needs.  


[1] Murder Among the MormonsDirected by Jared Hess and Tyler Measom. BBC Productions, 2021. Netflix,

[2] “How Two Document Examiners Solved the Case of the Salamander Letter.” Western Forensic Document Examiner, 12/05/2019. 

[3] Jones, Robert A., “The White Salamander Murders: Mark Hofmann’s Discoveries Had Shaken the Mormon Church.: Then a Bomb Went Off. And Then Another.” Los Angeles Times, April 5, 1987. 

[4] Keim, Brandon, “Stone Age superglue: a first sign of intelligence?” Wired, May 13, 2009. 




Posted by CatherineCerasuolo
June 14, 2021

CPG’s Boston Office Is Relocating to Woburn in August 2021


Cambridge Polymer Group, a premier contract R&D lab supporting medical device, pharmaceutical, consumer products and industrial companies, is moving to a new 17,000 SF facility on August 5, 2021. After two decades in Boston’s Charlestown neighborhood, CPG is relocating to Cummings Properties’ TradeCenter 128 campus in Woburn to accommodate rapid growth.

Conveniently situated on Route 128/I-95 on the Burlington/Woburn line, the new facility was chosen to fulfill Cambridge Polymer Group’s requirement for a large, customizable, highly technical space. The 117% increase in custom-built lab space will allow us to meet the growing demand for our varied, specialized analytical testing and research & development services. The additional capacity accommodates the ongoing expansion of our product development, chromatography, and extractables & leachables departments.

Since the Woburn site is only 12 miles north of our Charlestown location, CPG will be retaining existing staff. The 11% increase in office space provides room for a welcoming reception area, a spacious conference room, and more cubicles and offices, allowing for the acquisition of additional team members. Our new location offers plenty of free parking for both employees and visitors.

As an ISO 9001:2015 certified and ISO 17025:2017 accredited (Cert # 3930.01) testing laboratory, CPG takes quality very seriously. We are implementing a carefully planned phase approach to the relocation, designed to ensure a smooth transition. Our plan minimizes workflow disruptions and meticulously maintains the integrity of project research and instrument calibration.


Cambridge Polymer Group, Inc.
100 TradeCenter Drive, Suite 200
Woburn, MA 01801

Our contact numbers will remain the same, including our main number: 617-629-4400.


As of July 30, 2021, we will no longer be able to accept samples at 56 Roland Street, Suite 310, Boston, MA 02129. A sample submission form with our new location details is posted on our website and linked in our email signature.

For RFQs, sample submission questions, and PO submissions, please contact or call 617-629-4400, ext. 2.

If you would like to see Cambridge Polymer Group’s new space and meet our team of PhD problem solvers, please email to schedule a visit.


Shipments should be delivered to our dedicated loading dock. For questions about deliveries, contact Receiving at or 617-629-4400, ext. 21.

For Accounts Payable inquiries, please contact or 617-629-4400, ext. 3. 

We look forward to continuing to work with you at our new address. 

Posted by CatherineCerasuolo
May 10, 2021

What's in Your Supplement?

Deformulation of a Curcumin Nutraceutical By LCMS

Curcumin nutraceutical.jpg

Turmeric, the orange-yellow root of the Curcuma longa, has been used as a spice, medicine, and dye for at least 4,500 years. Turmeric consists of hundreds of compounds, but the curcuminoid curcumin is a major component of most commercial extracts. Although recent lab and animal research has found curcumin to contain anti-inflammatory and antioxidant capabilities, curcumin’s efficacy in human trials remains controversial, and trials have been limited due to its lack of oral bioavailability and rapid plasma clearance.  

Drug vs. Supplement 

Although the pharmaceutical industry has thus far viewed curcumin as a poor therapeutic agent, the nutraceutical industry does not have to prove efficacy to market curcumin for the treatment of disease. Because dietary supplements are not subject to the same FDA regulations as pharmaceuticals, there are currently no requirements that supplement labels be proven accurate or truthful. As a result, some marketed supplements contain less, or sometimes none, of the active ingredient they claim to contain.  

In a recent application note, Cambridge Polymer Group used liquid chromatography-mass spectrometry (LC-MS) to evaluate the curcuminoid content of a curcumin supplement relative to the claims made on the label. 

Product Deformulation  

Samples were obtained from a commercial supplement with a label indicating 180 mg of curcumin per capsule. Curcumin purchased from Sigma Aldrich was used as a control.  The percentage of curcumin in the control was consistent with the percentage reported by Sigma Aldrich's label.  

However, CPG found 40% less curcumin in the commercial curcumin supplement than advertised on its label. This deformulation shows that it is important for manufacturers to screen incoming raw materials for purity using validated testing techniques.  

Additionally, manufacturers can voluntarily submit products for certification by either the United States Pharmacopeia (USP) or National Science Foundation (NSF). A seal from either of these groups indicates that the consumer can trust that the product has been verified to contain the ingredients listed. As an ISO 17025 accredited and 9001 certified lab, CPG can test to USP standards and certify results. 

Read more

Posted by CatherineCerasuolo
January 27, 2021

Molecular Weight of Dextran by USP Method


Dextran, a polysaccharide made from glucose, is widely used in the medical field for treatment of shock, as an antithrombotic agent, to reduce blood viscosity, and as an anticoagulant. The two most common forms are dextran 40 and dextran 70 (the 40 and 70 refer to their molecular weights, nominally 40,000 and 70,000 g/mol).

The USP monographs for dextran 40 and 70 describe a specific gel permeation chromatography approach that differs in success criteria from other GPC methods, and requires a unique GPC system setup and data analysis method. To qualify a dextran formulation under these USP guidelines, the material must be tested by this GPC method.

A calibration curve is constructed with dextrose and five dextran standards of known molecular weights, using either a Gauss-Newton method or the Nilsson-Nilsson method to determine the constants in the expression below for each of the standards based on their reported molecular weights Mi.

Mi = b5 + exp(b4 + b1Ki + b2Ki2 + b3Ki3)

Each of the standards must meet a rigorous accuracy check to ensure the GPC system is adequately set up to test the specific dextran samples and to ensure they meet the requirements of the USP monographs. Once the equipment is properly validated by this method, the samples can be tested.

CPG is experienced in this USP test method for dextran GPC analysis. Contact one of our scientists for more information.

Posted by CatherineCerasuolo
December 24, 2020

The Gift of the Methyl Group Magi


A CPG twist on a holiday classic, with happier results

Paraxanthine and Theophylline sat at their Thanksgiving table.
“What have I got to be thankful for?” grumbled Xan. “No one’s ever heard of me. Caffeine gets all the hype, even though I’m more potent with less of the negative side effects. I want to be recognized for being better at blocking adenosine receptors. I want to see my formula on t-shirts and mugs! I want to be the name people whisper desperately as they stumble towards their kitchens.”
“If you don’t like your life, change it,” suggested Theo.
“Self-help mantras are well and good for humans, but what’s an organic compound to do? The holidays are so depressing. Another year gone by, and what have I got to show for it?”
While Xan continued to whine about the winter of her discontent, Theo googled “Formulation and Chemical Synthesis” and requested a quote from Cambridge Polymer Group.
Theo announced, “Xan, I’m going out now to get you a present. I’ll be back in 10-15 days.”
This revelation distracted Xan from her navel gazing. “Theo is getting me a gift??? I wonder what it could be?”
Ten days later, FedEx left a package on Xan’s doorstep. She rushed out to grab the box, which was almost stolen by porch pirates.
“Maybe it’s Theo’s present,” Xan thought excitedly. She opened the package and nearly lost her electrons when Theo jumped out of the box.
“Theo, is that really you?” Xan eyed him suspiciously, “You look a little different…”
“Here Xan,” said the Caffeine formerly known as Theo, “Have a carbon dihydride. If you can’t beat ‘em, join ‘em.”
“Oh, thanks so much,” gushed Xan, as she accepted his gift. “But now I’m Caffeine and you’re not, and I have nothing to give you.”
“That’s OK, Xan-I mean, Caff. I gave you my position 1 carbon dihydride, so I’m Theobromine now. We can be chocolate together.”
Box of chocolates.jpg

Total ion chromatogram of 4 chocolate samples showing peaks of caffeine and theobromine in water extraction.

Posted by CatherineCerasuolo
July 13, 2020

New Standard on Qualification of Polymeric Materials Used for Additive Manufacturing


ISO and ASTM are drafting a new standard on qualification of polymeric materials used for additive manufacturing using powder bed fusion (ISO/ASTM DIS 52925:2020). This standard is focused on polyamide 12 and 11, but the standard may be applicable to other polymeric materials.

The standard discusses the following test methods:

  1. Particle size
  2. Residual monomer
  3. Relative humidity
  4. Melt flow index
  5. Molecular weight (either by GPC or dilute solution viscometry)
  6. Melting and crystallization temperature by DSC

These tests are all performed by Cambridge Polymer Group, and can be used to qualify new material or requalify used material. Contact us for more information.

Posted by CatherineCerasuolo