Analysis of Sugar Free Soft Drinks

The new ultra fast scanning detector from Cecil Instruments, the CE4300, was used as part of an Adept System 4S to separate, identify and quantify the components of soft drinks.

Using the CE4300, high quality UV-Visible spectra were obtained “on-the-fly” without the use of an expensive Diode Array Detector.

The spectra indicate the most appropriate wavelength for monitoring any given material. The spectrum together with retention time data is sufficient to provide positive identification of separated peaks.

The chromatographic separation of commonly occurring components of soft drinks and fruit juices is shown.

The gradient elution used a C18 column, with a phosphate buffer : methanol binary gradient, monitored at 210nm as some of the components lack chromophores at longer wavelengths.

The UV absorption of methanol at 210nm is responsible for the sloping baseline in the latter part of the gradient.

The peaks in the chromatogram were scanned “on-the-fly” during elution and the spectra displayed in adjacent windows.

Four scans are shown here, overlayed. Sufficient information is available to identify a component peak when taken in conjunction with the retention time.

Versatility

• Highest sensitivity VWD
• Very low noise
• Very low drift
• Method storage
• Dual wavelength operation
• Programmed monitoring of six wavelengths
• Simultaneous 4 wavelength monitoring