phosphates in DDGSOur Applications Lab in Sunnyvale, California, recently released this application note featuring an ion chromatography method for the analysis of Dried Distillers Grains with Solubles (DDGS). This is the third and last in our series of applications notes covering the analysis of DDGS, a byproduct of ethanol production from corn. The previous two application notes are featured in the following blog posts:

As described in the previous application notes, DDGS are the dried remains of the production of ethanol from corn by fermentation and are sold for animal feed. Their mineral content must be known so that the feed can be properly formulated to ensure that the animals are getting the proper nutrition. A total phosphorous determination does not yield the necessary information because phosphate present in phytic acid and other inositol phosphates is nutritionally unavailable. Hence, DDGS are supplemented with inorganic phosphorus to meet the dietary needs of nonruminant animals. Additionally, processing factors such as fermentation, drying, and pelleting contribute to the nutritional variation in DDGS, and, therefore, it is important to determine phosphorus bioavailability for nonruminant animals.

Application Note 1070, Determination of Inositol Phosphates in Dried Distillers Grains with Solubles, (downloadable PDF), presents a rapid and reliable method that simplifies sample preparation of the DDGS samples by eliminating the traditional capture/release procedures and sample drying steps. This is done by using two sample preparation cartridges (Thermo Scientific Dionex OnGuard II RP Cartridge and Thermo Scientific Dionex OnGuard II AG/H Cartridge) in series. The Dionex OnGuard II RP cartridge removes interfering hydrophobic compounds and the AG/H cartridge removes excess chloride ions in the extraction solution that would otherwise overload the column.

Using our latest high-pressure ion chromatography system (Thermo Scientific Dionex ICS-5000+ HPIC system) equipped with our variable wavelength detector (Thermo Scientific Dionex VWD-3400RS Variable Wavelength Detector) and one of our carbhohydrate columns (Thermo Scientific Dionex CarboPac PA100 Analytical column), our chemists were able to separate 25 inositol phosphate peaks in an in-house prepared reference standard and a DDGS sample in less than 45 min.

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By the way, this application should also be of interest to biologists analyzing tissues and plant materials for inositol phosphates.

Do visit our biofuels webpage for more chromatography applications; we also have a small but growing library of chromatography research articles and applications on this blog that you might find interesting.

Do enter any questions you might have on this solution or the application note in the Comments box below; our experts will be pleased to hear from you.