Enhancing the Analysis of Beneficial Fats in Conventional Foods

Not all fats in the human diet are bad. Omega-3 fatty acids actually may help reduce the risk of heart disease by elevating the level of HDL or "good" cholesterol in the bloodstream.

Recently, the US Food and Drug Administration (FDA) issued a ruling that allows food producers to market the beneficial effects of Omega-3s. Specifically, the FDA is allowing product labeling for two Omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These are found primarily in oily fish like albacore tuna, salmon, mackerel, herring and sardines. EPA and DHA are also available in dietary supplements derived from fish and other natural sources.

Separating complex mixtures

The most practical method for measuring Omega-3 fats is gas chromatography (GC) using a high cyanopropyl-content capillary GC column. Omega-3 analysis also requires a high-polarity column with specific selectivity and very high efficiency. In the past, this type of column has been difficult to manufacture reliably, limiting its availability.

Agilent recently introduced the HP-88 column, which has been designed to separate complex mixtures of fatty acid methyl esters (FAMEs). The column is especially suitable for determining Omega-3 content via GC analysis of FAMEs—an approach that will separate Omega-3 FAMEs from 67 other FAMEs in 20 minutes.

FAME separations require very high column polarity and specific selectivity to separate molecules that have extremely subtle vapor pressure differences. These separations also require a very high number of theoretical plates, which means the column coating must be applied evenly and efficiently. The HP-88 column is optimized to ensure that its stationary-phase polymer will coat properly, minimizing the production problems that can cause long waiting times and unpredictable delivery.

Improving thermal stability

The HP-88 is comparable to the previous generation of cyanopropyl-containing columns, providing equivalent (excellent) resolution and nearly identical elution order. Its innovative internal chemistry also provides a temperature range that is 20º Celsius higher than similar columns. The improved thermal stability of the HP-88 reduces column bleed and increases column lifetime.

This long-lasting, high-resolution column enables efficient, reliable analysis of fatty acid content in conventional foods. For those companies that are updating their product labels, the HP-88 column provides accurate assessment of Omega-3 content—and it's available now.

For more information

To learn more about the HP-88 and the characterization of FAMEs, download a copy of the poster presented by Agilent and Lipomics Technologies at the September 2004 AOAC International meeting and exposition. To learn more about the HP-88 and other Agilent GC columns, please see the Columns & Accessories section of our Web site. For additional information about Agilent chemical analysis products and resources, please visit the Life Sciences/Chemical Analysis main page.