A Modern Apparatus for Performing Flash Chromatography: An Experiment for the Organic Laboratory.
A modern apparatus for performing flash chromatography using commercially available, prepacked silica cartridges has been developed. The key advantage of this system, when compared to traditional flash chromatography, is its use of commercially available silica cartridges, which obviates the need for students to handle silica gel. The apparatus has been tested for its ability to perform separations that are commonly found in organic chemistry teaching laboratories, and a laboratory module that combines the techniques of thin-layer chromatography, gas chromatography, and flash chromatography is described. The performance of this new chromatography apparatus was comparable to a traditional flash chromatography column.
Undergraduate Separations Utilizing Flash Chromatography
This article describes the procedures used to carry out four flash chromatography experiments: the isolation of the carotenes, chlorophylls and xanthophylls from a spinach extract; the separation of s-carotene from tetraphenyl cyclopentadienone; the isolation of (+) and (-) carvone from caraway and spearmint oil; and the purification of benzil from benzoin. Apparatus used is nonbreakable, easy to use, and inexpensive.
A dose‐response relationship between the frequency of p53 mutations and tobacco consumption in lung cancer patients
Mutations of the p53 tumor suppressor gene are frequent in lung cancers. It is suggested that p53 mutations are associated with smoking‐induced lung carcinogenesis. We examined p53 mutations in 53 lung cancers by analyzing reverse transcription‐polymerase chain reaction‐single strand conformation polymorphism (RT‐PCR‐SSCP) to ascertain the association between p53 mutations and smoking. Twenty‐five (47%) of 53 lung cancers carried p53 mutations. A discriminant analysis showed that the Brinkman index (0.156) and gender (0.140) significantly influenced p53 mutations. Furthermore, there was a dose‐response relationship between the quantity of cigarettes consumed and the frequency of p53 mutations in lung cancer patients (P < 0.001). In patients with adenocarcinoma, the frequency of p53 mutations correlated with the amount of the tobacco smoked (P < 0.05). We suggest that the p53 gene is a target of particular carcinogen in tobacco smoke. © 1996 Wiley‐Liss, Inc.