Principles of hot plate chromatography

Abstract

expedition. For this purpose, the average N20 value was determined from each pair of parallel measurements. The deviations of the corresponding single values from this average were used to calculate a quasi standard deviation, whose percentage from the average of all measurements of one expedition was ±1.7% for the 1970 expedition and ±1.45% for the 1971 expedition. As mentioned previously, for 15-to 20-liter air samples the standard deviation from laboratory experiments was ±1.4%. Accordingly, the ac ual accuracy aboard ship is comparable with that from laboratory experiments. The slightly increased value from the 1970 expedition may be due to unfavorable weather conditions.At some stations in the Atlantic Ocean, parallel samples were taken from the sea surface water. The N20 values from these parallel samples suggest an actual accuracy for N20 measurements in sea water aboard ship better than ± 3 %.In a recent paper, LaHue et al. ( 8) described an analytical method for measurements of the atmospheric N20. This

TLC [thin-layer chromatography]. Programmed multiple development

“…Heated Bed. In one heated-bed variation, Turina et al (10,11) raised the temperature of the thin-layer plate during development; and in another, provided a zone of sharp temperature increase across the plate. Raising the temperature of the plate during development increased both sensitivity and resolution.…”

“…Raising the temperature of the plate during development increased both sensitivity and resolution. With a "high-resolution zone" across which the temperature of the developing solvent rose sharply in the direction of development, both resolution and sensitivity were highly improved within the zone (11).…”

The thin layer chromatography of vat dyes

“…For example, when 21 vat dyes were chromatographed with eluent 1 (nitrobenzene and I-chloronaphthalene (5:5)), the chromatogram at 120°C showed higher Rf values than that at 1OO"C, with the obvious exception of dyes that remained at the origin. This could be attributed to a change in the solubility of the solute in the mobile phase as well as to the interactions between the sorbent and mobile phase [17,18].…”

“…The use of elevated temperature in t.1.c. in general [17,18], and in the separation of indigo and a limited number of vat dyes Table 1 Vat dyes used in t.1.c. analysis and intermediates in particular [19], has been reported.…”

The steps about the three Dimensional Modeling of Bioprosthetic Heart Valves Based on CT Images

“…Medical imaging is a subject that uses the methods of medical imaging for medical services. It is not only used for non-invasive examination of medical diagnosis and anatomical structure of human body, but also used in computer simulation and operation simulation in the analysis of engineering field [5,6]. As you know, the structure of the human heart valve is special, and the surface of the valve is changed obviously.…”