Industry: Food and Beverage
Instrument: AQUATek 70 Vial Autosampler
Low-level Analysis of Sulfur Compounds in Beer by Purge and Trap
Low levels of sulfur compounds in beer are known to have drastic effects on flavor and aroma. Levels as low as 0.1 ng/ml for compounds such as thiols, can affect flavor and are indicators of variations in the brewing process. This makes it essential for the modern brewing industry to detect and monitor sulfur compounds in beer. In the past, the detection of such low levels of sulfur compounds was limited by the reactivity of the sulfur compounds with nickel tubing and stainless steel fittings within the analytical equipment. This made it difficult to recover analytes at low levels.
The quantitative analysis of low-level volatile sulfur compounds in beer is fully automated with the Tekmar-Dohrmann AQUATek 70 and 3100 Sample Concentrator. A Hewlett-Packard 6890 Gas Chromatograph (GC) with a Sievers Model 355 Sulfur Chemiluminescence Detector was used for this analysis. The sample pathway of the 3100 Sample Concentrator is completely Silcosteel creating the perfect pathway for sulfur compounds. Low-level sulfur compounds do not adsorb or decompose on the inert Silcosteel surface. This surface is composed of a layer of inert fused silica coating the inside of the sample pathway.
The results show the detection limits achieved for sulfur compounds found in beer and the repeatability of the results. A comparison of two gas chromatograph column types used for this study, a J&W GS-GasPro and a J&W DB-1 are also shown.
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