VUV Analytics launches updated gas chromatography detector
The VGA-101 gas chromatography (GC) detector was unveiled at the 40th International Symposium on Capillary Chromatography (ISCC) in Riva del Garda, Italy.
It samples at up 100 Hz, and has a spectral bandwidth of <1 nm with wavelength accuracy of ±0.2 nm with analyte sensitivity typically in the low ppb.
The instrument builds on the VGA-100 in 2014 and SVGA-100 in 2015.
How does it work?
Asked about how VUV absorption spectroscopy works, Paul Johnson, senior product marketing manager at VUV Analytics, said it uses the wavelength range of 120 – 240 nm which has never been used in a commercialized instrument.
“The VUV absorbance region is an ideal fit with gas chromatography detection due to the fact that almost every chemical compound absorbs strongly in this wavelength range,” he told FoodQualityNews.
“Photons in this regime are capable of producing electronic transitions in virtually all chemical bonds, especially from a ground state to an excited state designated as σ→ σ* and π→ π* transitions, which cannot be probed in traditional UV/Vis spectroscopy utilized in LC-based systems.
“The result is VUV spectral data that provides both unambiguous identification and mass quantitation of compounds including co-eluting isomers.”
Johnson added GC-VUV methods last anywhere between seconds and hours depending on the length of the chromatography method but an advantage of VUV spectroscopy is chromatographic baseline separation is unnecessary due to the ability to spectrally deconvolve co-eluting compounds.
The VGA-101 features an expanded wavelength, higher maximum allowable operating temperature, and in-line GC compatibility.
It has the ability to run at operating temperatures exceeding 400° C and measurement between 120 – 430 nm.
The firm said ‘engineering advancements’ have resulted in gains in sensitivity and enhanced signal to noise at lower wavelengths.
Applications in F&B
Johnson said one area of food and beverage analysis that the VGA-100 demonstrated use in is fatty acid methyl ester (FAME) characterization.
“We have shown the ability to consistently classify FAMEs as saturates, monounsaturates, or poly-unsaturates, while simultaneously distinguishing between cis and trans isomeric mono and poly unsaturated FAMEs,” he said.
“The higher S/N gains at lower wavelengths, spectrum expansion to 430 nm, and higher operating ranges are anticipated to provide a more complete view of this FAME spectral data and lead to new insights in F&B applications such as food adulteration.”
The VGA-100 deals with matrix interference by using spectral deconvolution to distinguish the analyte of interest’s absorbance contribution from other compounds in the mixture.
The deconvolution method is based on a linear Beer’s Law relationship and is automated in the VGA software.
Sean Jameson, SVP of business development at VUV Analytics, said: "Responding to our customer's feedback, the VGA-101 detector is uniquely engineered to provide qualitative and quantitative GC data with excellent sensitivity and selectivity at elevated operating temperatures throughout an expanded wavelength spectrum."
