Advancing Adhesives
Purity Determination Without a Known Chemical Standard

Unlike previous generations of DSC devices, Impact Analytical’s new design measures true heat flow, rather than temperature differential, for more accurate caloric determinations.
Manufacturers of fine chemicals and pharmaceuticals can now obtain precise evaluation of material purity, including a Certificate of Analysis as documentation, even in the absence of a recognized purity standard.

Using the proven technique of differential scanning calorimetry (DSC), a new service offered by Impact Analytical, Midland, Mich., allows determination of absolute purity based on the well-recognized premise that even small amounts of impurities lower the melting point of a material and broaden its overall melting range. With standards of known purity not readily available for many pharmaceutical and organic materials, the new service helps simplify documentation and reduce time to market.

“This technique is based on ASTM Standard E928-01, which details the use of DSC for assessing purity,” explained Impact Analytical’s Lynn Walker, who was a contributor to the ASTM guidelines. “The method is effective on very small sample sizes, and turnaround is quick,” he said.

Instrumental Advancements

Since its commercial introduction in the 1960s, DSC has proven to be a rapid, precise and easy-to-use approach for evaluating the purity of many different types of materials, but recent advancements in instrument design and accuracy have significantly enhanced its utility. Impact Analytical uses a PerkinElmer power-compensated DSC instrument, with very low mass furnaces on the sample side and reference side to deliver critical rapid-response times needed for purity measurements.

Unlike previous generations of DSC devices, the new design measures true heat flow, rather than temperature differential, for more accurate caloric determinations. In addition, unique platinum resistance thermometers (or PRTs) deliver fast response, providing accurate and precise measurements of sample temperature, which are critical to absolute purity assessment. With the instrument’s outstanding resolution and very high sensitivity, scientists can obtain more theoretically correct melting responses (narrow-peak half-width and greater peak intensity).

The device features sophisticated software with multiple linear regression analysis for determining the purity of materials that undergo simultaneous melting and decomposition. The power-compensated DSC approach also yields well-defined partial heat of melting intervals without the “smearing” effect, which can occur with heat-flux DSC devices.

For more than 25 years, Impact Analytical has provided problem-solving capabilities, detailed analysis and method development to customers in manufacturing and academia. The company’s technical personnel also help customers implement quality-control programs, certify suppliers and characterize unknown materials. With considerable resources in polymer science, Impact Analytical maintains resident expertise in process engineering, packaging and physical-properties testing. The laboratory is registered under ISO 9001.

For more information:

For more information, contact Impact Analytical, 1910 W. St. Andrews Rd., Midland, MI 48640-2696; phone 989-832-5555; fax 989-832-5560; e-mail; or visit

Did you enjoy this article? Click here to subscribe to Adhesives & Sealants Industry Magazine.

You must login or register in order to post a comment.



Image Galleries

ASI April 2014 Photo Gallery

Our April 2014 issue is now available!


ExxonMobil Tackifier Expansion

Dwight Tozer, vice president of ExxonMobil’s Adhesion Industry business, discusses the company’s latest tackifier expansion project with Editor-in-Chief Susan Sutton.

More Podcasts

Adhesives & Sealants Industry Magazine

ASI July 2015 issue

2015 July

The July issue features our annual Distributor Directory! Be sure to check it out!
Table Of Contents Subscribe

"Cultural Fit"

A recent opinion piece in the New York Times observed that new employees are often hired based on the personal similarities they share with their interviewers. How important is “cultural fit” when hiring someone?
View Results Poll Archive


Handbook of Sealant Technology

The Handbook of Sealant Technology provides an in-depth examination of sealants, reviewing their historical developments and fundamentals, adhesion theories and properties, and today’s wide range of applications.

More Products

ASI 2014 Buyers GuideASI's Buyers' Guide

Annual purchasing resource for equipment used in the manufacture/formulation of adhesives, sealants, pressure sensitives, tapes and labels and for application of finished adhesives. 


facebook_40px twitter_40  youtube_40pxlinkedin_40 google+ icon ASI 30px

Clear Seas Research

With access to over one million professionals and more than 60 industry-specific publications, Clear Seas Research offers relevant insights from those who know your industry best. Let us customize a market research solution that exceeds your marketing goals.