Quantitative ultraviolet measurements on wetted thin-layer chromatography plates using a charge-coupled device camera

This paper presents the first study of the UV imaging of spots on thin-layer chromatographic plates whilst still wet with solvent. Imaging of spots of benzophenone during and after development was carried out using a charge-coupled device camera. Limits of detection were found to be 5 ng on a wetted plate and 3 ng for a dry plate and the relationship between peak area and sample loading was found to be linear in the low nanograrn range over an order of magnitude for both wet and dry modes with r(2) values > 0.99. It was found that UV measurements on wet glass-backed plates suffer from low sensitivity; however, the use of aluminium-backed plates gave increased sensitivity. The apparent absorption coefficient (epsilon(app)) of 10AU m(2) g(-1) at 254 nm is consistent with reflection of the light from the aluminium surface with a double pass through the sorbent layer, and suggests that use of aluminium-backed plates should enable monitoring of separations by UV absorbance during TLC development. (c) 2008 Elsevier B.V. All rights reserved

Judge Learned Hand and the Limits of Judicial Discretion

Learned Hand stands among the great judges of the Anglo-American legal tradition. He is preeminently the judge\u27s judge. His long judicial career, spanning one of the crucial periods in the development of American law, and his long service on the bench in a circuit where crucial legal issues come into final focus and where a major part of the commercial law of the nation is first enunciated and explained, peculiarly fit him for the task of explaining the judge\u27s function in the American system of law and the court\u27s role in our jural order. His own legal experience, his non-official writings, brief as they are, and his official opinions are the sources from which his views as to the limits of judicial discretion may be determined. Sir Frederic Pollock has said that the duty of the courts is to keep the rules of law in harmony with the enlightened, common sense of the nation, \u27 for the accomplishment of which caution and valor are both needed, caution in making advances which have not become generally acceptable and valor in dispensing with technical difficulties and in overriding what is merely a show of authority on the part of current opinion. If this be the true measure of judicial activity, certainly Judge Learned Hand has filled nicely the judge\u27s role. He has achieved this happy balance between caution and valor which is at once the hallmark and the insignium of merit of great judges