Trapping efficiency of aqueous pollutants in multichannel thick-film silicone-rubber traps for capillary gas chromatography

Alternatives for characterizing macroporous polyacrylamide monolithic ion exchanger columns

“…Some other studies with cryogels reported asymmetry of the RTD experimental curves and the use of the half‐peak height method to determine the total number of theoretical plates and consequently of HETP values . According to Bidlingmeyer and Warren , Ortner and Rohwer , and Guiochon , the method of moments results in fewer errors and is not affected by peak asymmetry, which is not the case with the other methods, such as the half‐peak height method, 3 σ , 4 σ , and 5 σ , and others.…”

“…The use of the method of moments to determine the retention times and variance of the samples was shown to be adequate, since, considering the asymmetry observed, other methods could have resulted in greater errors . Figures and show the values obtained for apparent axial dispersion coefficient and HETP.…”

Sorption of volatile organics from water using an open-tubular, wall-coated capillary column

“…1. 11,12 The curve fitting option in the Origin graphics program (MicroCal Software Inc., Northampton, MA, USA) was used to obtain the equation of the curve. Integration of the Boltzmann equation gives an estimate of the total sorbed solute amount, which is represented by the shaded section in the figure . From the profile, the volume of the sample solution needed for the extraction to reach equilibrium can be obtained.…”

Spray desorption collection of free fatty acids onto a solid phase microextraction fiber for trap grease analysis in biofuel production

“…24 While HS-SPME is a sampling technique that typically works under static equilibrium conditions, many variations have been developed where trace chemicals are sampled from large volumes of gas or liquid. [25][26][27] These systems are variations of regular SPME sampling methods to provide the most efficient extraction of compounds from a non-equilibrated system. Purging volatile chemicals by a stream of air (sometimes accompanied by a small amount of solvent) from solid materials for SPME sampling was previously reported.…”