LFE CORPORATION

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LOW TEMPERATURE ASHER NEW IMPROVED PERFORMANCE A T A NEW LOW PRICE INCREASED ASHING RATES: • improved oxidation chamber design • optimum sample "boat" design • 300 watts of R.F. power output • improved power coupling efficiency NEW FEATURES: • manual or patented automatic sample boat agitation • controls and logic for automatic pump-down and slow purge to pre­ vent sample-residue disturbance or accidental loss AREAS OF APPLICATION: The LFE Low Temperature Asher is used in the separation and high percentage re­ covery of inorganic trace elements from an organic matrix of a food, biological, chemical, or pharmaceutical sample prior to spectrochemical analysis. In addition, the LTA is used for the separation of particles from filter matrices for study of air pollution samples. Try it in your laboratory. Call LFE for further information or for a free demon­ stration.

AVAILABLE UNDER GENERAL SERVICE ADMINISTRATION CONTRACT NUMBER GS-00S-26753

Process Control Division CORPORATION

1601 Trapelo Road Waltham, Massachusetts 02154 (617) 890-2000

CIRCLE 128 O N READER SERVICE CARD

Quantitative TLC in any mode...with one j ^— j"»-t-*JH 4 . » » ΓΊ . » 1 The Schoeffel SD3000 Spectrodensitometer ΐ 1 M S Î . Π , Ι - Μ . , Η . Τ Γ ^ Μ . Ι . 1 - P rov 'des accurate and reliable quantitative data automatically for plates, film and gels. The user can select reflectance, transmission or fluorescence modes quickly and easily. To extend the versatility of the popular SD3000, Schoeffel has added the SDA600 Fluoroscan for the scanning of emission spectra of separated compounds. For precise plate positioning, another new accessory is now available the SDA400 X-Y plate positioner. The SD3000 is a full, double-beam instrument with a wavelength range of 200 to 700 nm. This eliminates the need to stain separations on plates or gels.

Send today for complete technical literature. 24 Booker Street Westwood, N. J. 07675 (201) 664-7263

SCHOEFFEL INSTRUMENT CORPORATIC

CIRCLE 189 ON READER SERVICE CARD 204 A · ANALYTICAL CHEMISTRY, VOL. 48, NO. 2, FEBRUARY 1976

Books to assemble the spectra into a wall chart approximately 2 X 7 ft in size. One other noteworthy feature is the chapter on theoretical analysis of mo­ lecular vibrations which contains a de­ tailed example of the chloroform mol­ ecule, complete to the substitution of numerical values. Most chapters have been rewritten and improved over the first edition. New illustrations have been added. Relatively little new material on spec­ tral correlations has been added. This is no doubt a reflection of the maturi­ ty of this field. Some added material on group frequencies is related to the Raman effect, which still seems to have less coverage than infrared. The chapter on calculation of thermody­ namic functions has been omitted from the new edition. A few typographical errors have been detected. On page 146, for exam­ ple, the label for equation 3.28 has been misplaced. The only substantive error detected is on page 125: ". . . , a molecule cannot possess a threefold and a fourfold axis in the same direc­ tion." (This holds space groups, not point groups, i.e., molecules.) This is a useful reference book for practicing spectroscopists. It can also be recommended to nonspecialists as an informative survey of infrared and Raman spectroscopy. Methods of Enzymatic Analysis, Vol. 4. Hans Ulrich Bergmeyer. xxxix + 2302 pages. Academic Press, Inc., 111 Fifth Ave., New York, N.Y. 10003. 1974. $56

Reviewed by Myer M. Fishman, De­ partment of Chemistry, The City Col­ lege of New York, City University of New York, New York, N.Y. 10031 "Methods of Enzymatic Analysis", which has gone through several edi­ tions and printings, is now available as a four-volume treatise, a translation of the German edition which appeared in 1974. The editor, H. U. Bergmeyer, to­ gether with some 240 collaborators, all of whom are experts in their respec­ tive fields, has produced a text which maintains the high quality of the ear­ lier editions and continues to serve as an excellent standard reference both for the beginner as well as the ad­ vanced worker. In view of the fact that the total cost is somewhat high, some of the comments which appear below are made with this in mind. Volume 1 provides a general intro­ duction covering the importance of enzyme analysis, the principle of en­ zyme analysis (including a fine section on kinetics), a variety of experimental