Validation of Wisconsin Gasoline Range Organics
September 1st 2011The Wisconsin Department of Natural Resources (DNR) Modified Gasoline Range Organics (Wisconsin GRO) Method is used to determine gasoline and gasoline components in water and soil. The optimal hydrocarbon range is from C6-C10 with a boiling point range from 60 ?C–220 ?C (1). The analysis of Wisconsin GRO is vital in determining the "composition and the origin of such products including weathered fuels leaking from underground storage tanks, spills in pipe lines and run-off from surface transportation" (2).
Aggregation Analysis of Biosimilar EPO (Erythropoietin) Using a BioSep 2000 GFC Column
September 1st 2011Gel filtration chromatography is the primary method used to analyze the amount of aggregate and dimer present in a therapeutic protein sample. A BioSep 2000 column is used to analyze EPO samples to determine difference in the amounts of aggregate present.
Organic Acid Counter Ion Analysis using a Bonded Zwitterionic Stationary Phase
September 1st 2011Using a bonded zwitterionic stationary phase, ZIC?-HILIC, polar organic acid counter ions such as methylsulfonic acid can easily be retained, to aid simultaneous analysis of basic pharmaceutical APIs together with their counter ions.
"Green" Analysis of Diet Soft Drinks Containing Caffeine and Aspartame
September 1st 2011The popularity of diet soft drinks containing aspartame requires the analysis of thousands of samples for quality control purposes each year. These analyses are typically carried out with some fraction of organic modifier in the eluent, leading to the generation of thousands of gallons of hazardous organic waste. This note shows the "green" analysis of several commercial diet soft drinks in combination with a 100% water mobile phase.
HPLC Stevia Sweetener Analysis with CAD and UV Detection
September 1st 2011In December 2008, the United States FDA recognized rebaudioside A (reb. A) purified from Stevia rebaudiana (Bertoni) as Generally Recognized as Safe (GRAS) as a sugar substitute in foods. As a result, stevia products have become popular tabletop and beverage sweeteners. Two steviol glycosides, stevioside and reb. A, are largely responsible for the desired sweet flavor, with reb. A preferred for sweeteners (1).