Historically, brewers have used dry-hopping (a cold extraction of nonvolatile and volatile chemicals from hops into fermenting or finished beer) to increase the microbial stability and shelf life of their beer. As hoppy beer styles have gained in popularity over the last decade (2007-2017), the objective of dry-hopping has turned...
A gas chromatographic procedure was developed for the determination
of nanogram quantities of hydrocyanic acid using a
flame ionization detector. Excellent chromatograms were obtained
on a porous polyaromatic polymer column (Porapak Q) at 60°C. The
procedure was employed for the analysis of HCN in aqueous cyanide
solutions. Solutions as low...
A quadratic programming method was developed for the statistical
analysis of gas chromatographic data. The method was applied to
three types of flavor extracts, peppermint, hops and brewed tea. The
brewed tea data had to be abandoned because of the singularity of its
coveriance matrix. In all cases tried the...
In the study of gas chromatography a model is presented to simulate
a capillary gas chromatographic system. The model was developed
to study the concentrations of sample gas as a function of time and
space as it travels through the capillary column. The molecular migration
was approximated by elementary diffusion...
Gas-solid chromatography often has asymmetrical elution
peaks. This is attributed to nonlinear isotherms, multi-energy
adsorption sites, and slow processes. This study utilized a stopflow
gas chromatograph with various NaOH and NaCl modified
aluminas as adsorbents and methane as adsorbate to determine the
influence of surface area and pore volume distribution...
A classification of stationary liquids by infrared spectroscopy to evaluate the polarity was made using the solvent effect technique. The infrared C-Cl absorption frequency shift was measured for solutions of 1-chlorohexane dissolved in each stationary phase. These frequency shifts were correlated to the relative retention times of 1-octene/n-octane, trans-2-octene/n-octane and...