Search

Discography test associated with the scanner (discoscanner) is an exam that has been a renewed interest in recent few years. Thanks to the emergence of new interventions such as disc prosthesis, the procedures require confirmation of the disc level to deal with and the origin of discogenic symptoms. The aim of this paper is to describe the techniques, challenges and tips as well as the interpretation of functional and morphological examination.

The reaction between 2,2-dimethoxypropane and water to form acetone and methanol was applied to the determination of water in natural products by GLC. Water was extracted from the natural products with methanol and analyzed with a column of 30% tetrahydroxyethylethylenediamine on diatomite, using cyclohexane as an internal standard. Peak area ratios were used to calculate the water content. A linear relationship exists between the ratios of the observed peak areas of acetone to the internal standard and the actual weight ratios of water to the internal standard. The water content of 24 natural products representing a variety of plant parts was analyzed by GLC utilizing the above reaction. The results compare well with those obtained by gravimetric and azeotropic methods. The new method is simple, rapid, and has a very good precision and accuracy. A major advantage of the method is that water estimation can be carried out using a flame-ionization detector.

The use of gas–liquid chromatography was investigated as a means of determining the moisture content of crude drugs. Sixteen crude drugs representing a variety of plant parts and products were analyzed using this technique. Water was extracted from the crude drugs by disintegration with anhydrous methanol in a Waring blender and analyzed with a column of Teflon-6 coated with 10 percent polyethylene glycol 1500, using n-propanol as an internal standard. Peak height ratios were used to calculate the moisture content. The results obtained with the gas-liquid chromatographic procedure were quantitatively in accord with the results obtained by oven drying at 105° and toluene distillation methods. In addition, the new chromatographic procedure is simpler, more rapid, and has a very good precision (the maximum standard deviation was 0.36).

The effect of the extraction procedure on the recovery of water from crude drugs was related with its quantitative analysis by GLC. Some crude drugs seem to retain part of their water in a bound form, which is not available for extraction with methanol by disintegration in a blender but can be readily removed by boiling the product with the solvent under reflux for 1 hr. A number of crude drugs, representing a variety of plant parts and products, were extracted with methanol by the two procedures; the extracts were subsequently analyzed for their total water by GLC. Reflux extraction is the method of choice for the preparation of extracts of crude drugs that contain bound water prior to their analysis by this technique.