Gas Chromatographic Response as a Function of Sample Input Profile.

Reilley, Charles N.; Hildebrand, Gerhard; Ashley, J. W.

doi:10.1021/ac60190a008

Cited by 153 publications

(82 citation statements)

References 6 publications

(5 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The time-or volumedependent response of the sensor can also be modeled, although the derivation is not so simple, using theory derived from frontal chromatography. [52][53][54] We have developed this theory for the equilibration-based sensor and it is present in the manuscript in the Appendices.…”

Section: Equilibration-based Sensing Theory (Pnnl)mentioning

confidence: 99%

Radionuclide Sensors for Subsurface Water Monitoring

DeVol¹

2006

View full text Add to dashboard Cite

Section: Equilibration-based Sensing Theory (Pnnl)mentioning

confidence: 99%

Radionuclide Sensors for Subsurface Water Monitoring

DeVol¹

2006

View full text Add to dashboard Cite

“…Senum's chart is used as the template for Figure 3.7, except that the elution chromatography term (Vr, retention volume) has been replace with the frontal chromatography term (Vb, breakthrough volume). The terms v b and V, for an adsorbent bed are equivalent when v b is defined as the midpoint of the chromatographic front as shown in Figure 3.6 (Reilley et al 1962;You and Bidleman 1984). As seen in Figure 3.7, for a given N, the overall collection efficiency decreases as the sampling volume approaches the breakthrough volume (i.e., overall collection efficiency is inversely proportional to the V , N b ratio).…”

Section: Overall Collection Efficiencymentioning

confidence: 99%

Evaluation of an ambient air sampling system for tritium (as tritiated water vapor) using silica gel adsorbent columns

Patton¹,

Cooper²,

Tinker³

1995

View full text Add to dashboard Cite

SummaryAmbient air samples for tritium analysis (as the tritiated water vapor [HTO] content of atmospheric moisture) are collected for the Hanford Site Surface Environmental Surveillance Project (SESP) using the solid adsorbent silica gel. The silica gel has a moisture sensitive indicator which allows for visual observation of moisture movement through a column. Despite using an established method, some silica gel columns showed a complete change in the color indicator for summertime samples suggesting that breakthrough had occurred; thus a series of tests was conducted on the sampling system in an environmental chamber.The purpose of this study was to determine the maximum practical sampling volume and overall collection efficiency for water vapor collected on silica gel columns. Another purpose was to demonstrate the use of an impinger-based system to load water vapor onto silica gel columns to provide realistic analytical spikes and blanks for the Hanford Site SESP. Breakthrough volumes (VJ were measured and the chromatographic efficiency (expressed as the number of theoretical plates N) was calculated for a range of environmental conditions. Tests involved visual observations of the change in the silica gel's color indicator as a moist air stream was drawn through the column, measurement of the amount of a tritium tracer retained and then recovered from the silica gel, and gravimetric analysis for silica gel columns exposed in the environmental chamber.For all tests, flows were 1 to 1.5 L/min with the relative humidity at approximately 30 % . Visual observations and gravimetric tests were conducted from 20°C to 50°C. Tracer tritium recovery tests were conducted at 20°C and 40°C. The basic test apparatus was an air pump connected to a primary silica gel column (18-cm x 5.9-cm diameter) with flow rates measured and controlled with a rotameter. For the tracer tritium tests, an impinger was installed upstream of the primary column and a backup silica gel column was added to prevent loss of tritium to the test chamber environment. Samples were prepared for analysis by vacuumdistillation and counted by liquid scintillation. The visual observations yielded relative breakthrough volumes (air volume/adsorbent depth [m3/cm]) of 0.36 for 20°C 0.20 for 30"C, 0.15 for 40°C and 0.077 for 50°C. Average tritium tracer recoverieS at 20°C were 71 % with no observed breakthrough. Mean tritium tracer recoveries at 40°C dropped from 75% for volumes S3.0 m3, to 0% for a volume of 5.0 m3.Moisture loading and frontal chromatographic profiles were measured for water vapor migrating through the silica gel columns. Moisture indicating silica gel was packed into a 5-segment column, using metal screens to divide the segments. Moist air was drawn through the column until the third segment showed a partial color change of the indicator. The mlumns were disassembled and each segment was weighed and the moisture content was calculated. Moisture loadings (g H,O/g silica gel)ranged from 0.063 to 0.16 for the first and second segments, 0.027 ...

show abstract

“…The effect of rectangular input pulse duration on the shape of an output elution curve was studied in [10], where the elution curve was, in accordance with the solution obtained in terms of the plate theory [4] in which the adsorbent length is assumed to be infinite, represented by a Gaussian function. No qualitative variations in the elution curve shape were revealed as depending on the duration of the input pulse in [10].…”

Section: Introductionmentioning

confidence: 99%

The effect of input pulse duration on the elution curve profile

Larin

2014

Colloid J

View full text Add to dashboard Cite

Numerical simulation and new analytical solutions have been used to study the effect of the dura tion of the input pulse of an adsorbate on the development of the elution curve profile in the adsorption dynamics. Elution curves calculated with regard to finite input pulse duration have been compared with those determined for the instantaneous injection of an adsorbate in the absence of extracolumn broadening. Quan titative regularities of variations in curve parameters measured as the time corresponding to the maximum of the curve and its width at a fixed height as depending on the length of an adsorbent layer have been estimated. The influence of the input pulse duration on the statistical moments of the elution curve has been determined, with the obtained moments being in agreement with the published solution that was previously found using the Laplace transformations. Correspondence between the theoretical and experimental data has been revealed for argon elution from a helium flowing through an activated carbon layer.

show abstract

Gas Chromatographic Response as a Function of Sample Input Profile.

Cited by 153 publications

References 6 publications

Radionuclide Sensors for Subsurface Water Monitoring

Radionuclide Sensors for Subsurface Water Monitoring

Evaluation of an ambient air sampling system for tritium (as tritiated water vapor) using silica gel adsorbent columns

The effect of input pulse duration on the elution curve profile

Contact Info

Product

Resources

About