H. Shanfield

The preparation of analytically stable, immobilized stationary phase coatings on colums packing materials

SummaryA coating of silicone SE-54 on Chromosorb W has been converted to an analytically stable, immobilized stationary phase layer by cross-linking with an organic peroxide. Up to 10% by weight has been applied in this manner. Excellent high temperature qualities are exhibited, such as low bleeding and good base line stability, during typical analyses.Poly (2,6-dimethyl-p-phenylene oxide) has also been crosslinked as a surface coating on Chromosorb W with an organic peroxide. From 3 to 4% by weight has been immobilized in this way. The resultant packing material, following high temperature conditioning, has been examined for use as an adsorbent of trace substances, similar to the applications to which such adsorbents as Tenax GC have commonly been applied, e.g. trace analysis of air. It appears to exhibit satisfactory properties for this analytical purpose.

Fluorescence-inducing procedures for use in high-performance thin-layer chromatography

Abstract A comparison is made of three methods which have been previously employed to induce fluorescence in compounds, with particular reference to high-performance thin-layer chromatographic (HPTLC) chromatoplates. In addition, it has been found that the simple procedure of exposing the chromatoplates to HCl, HBr, or HNO3 room-temperature vapors, followed by heating, is sufficient to produce strong fluorescence in a wide variety of compounds. This brings to HPTLC the sensitivity advantages inherent in fluorescence as a visualization technique. In all cases, fluorescent spot intensity remained unchanged for at least two weeks.

Immobilization of silicone stationary phases on supports using ozone

SummaryImmobilization of silicone stationary phases, OV-1701 vinyl and OV-225 vinyl, on Chromosorb W-AW support was achieved in a simple procedure using ozone as an initiator. A column efficiency of 2400 theoretical plates/meter was obtained.

A new adsorbent for trace level organic contaminants

SummaryA preliminary study has been carried out to evaluate a new adsorbent, Thermosorb, for trace level organic contaminants. For this purpose, a comparison was made with a well-characterized adsorbent, Tenax GC, using a prepared aqueous solution of trace organic components. In addition, a comparison was made of chromatograms of air contaminants obtained using both of these adsorbents, under equivalent conditions. The results clearly indicated the potential of this thermally stable, inorganic adsorbent for many trace organic substances of environmental interest.

Concentration Techniques for Volatile Samples

The direct analysis of trace concentrations of many organic compounds stretches the very limits of, or completely defies, even the most sensitive analytical equipment. For many areas of research, substances of interest are often at or below the part per billion level.