CARLE INSTRUMENTS, INC

---

INSTRUMENTATION

New Concept for Undergraduate

Chemistry

Other uses include high speed scanning at a fixed wavelength of column effluents for the detection of a particular functional group such as carbonyls. In another application bearing no relationship to chromatography, the instrument can be used to study reaction rates in gas, liquid, or solid samples. When used as a single wavelength monitor, the appearance or disappearance of a particular band in components as short lived as 10 milliseconds can be recorded. Conversely, when used as a fast scan spectrophotometer, the instrument follows slower reactions by providing repetitive four-second scans in a series of continuous six-second cycles. Used in either fashion, the study of reaction intermediates can be performed by interpolation of the recorder time base.

BASIC GAS CHROMATOGRAPH Analytical chemistry is not the same as it used to be. Instrumentation has been displacing classical methods at an ever increasing pace. Leading educators have watched this trend with frustration because of budgetary limitations. It is particularly important that gas chromatography, the most revolutionary of the new techniques, be included in undergraduate chemistry programs. This is why Carle Instruments is proud to announce a major break-through in low-cost educational instrumentation, the Basic Gas Chromatograph. The new, simplified instrument is designed with emphasis on fundamental principles, as well as recent technological advances. The Basic Gas Chromatograph features dual Va" columns, dual on-column inlets, a micro volume thermistor detector, separate temperature control of columns, inlets and detector, and an upper temperature limit of 150°C. A transparent control panel exposes all circuit components, eliminating "black b o x " complexity. The instrument measures only 1 7 " x l 3 " x 4 " when the case is closed, allowing compact stock room stacking. Performance compares favorably with much more expensive instruments because inlets and detector are optimized in geometry and speed of response. Even though the Basic Gas Chromatograph is manufactured to the same high-quality standards as other Carle products, prices range from $375.00 for single instruments down to $337.50 in quantities of twenty-five units.

C A R L E INSTRUMENTS,

INC.

adapted to the rapid infrared analysis of fractions coming from a gas chromatograph. The Microspec instrument is supplemented by equipment regulating the inlet tube and sample cell temperature of the IR-102 so that they are at the same temperature as the sample coming from a chromatographic column. In this way, all trapping, transferring, and condensation problems are eliminated. In this technique, complete spectra from 2.5 to 14.5^ are produced in four seconds. Since the instrument employs an extremely fast thermal detector, it must be used with a high speed oscillographic type recorder such as the Beckman Model IiS.

532 South Rose Street Anaheim, California 92805 (714)533-4000

We find such original and novel approaches stimulating and exciting and a welcome relief from the routine applications of existing techniques. The spirit of such inquiry is epitomized by a slogan in another field. Sixteen years ago, the gifted Franco-American industrial designer, Raymond Loewy, described the true spirit of his craft. The title of his book was "Never Leave Well Enough Alone." The pedestrian type of researcher makes use of the simplest tools suitable for the job. It cannot be denied that many important discoveries have been based upon crude and relatively simple observations and that which was lacking in the way of evidence was more than compensated by shrewd insight and intuitive reasoning. In the limit, no measurements at all are required and this is the happy lot of the theoretician. The instrumentation expert will always be concerned with a new approach and however much respect and admiration he may show for fine achievement, he will seek a new and better method. Spectrophotometry is not a closed book— there is much still to be done even though the latest chapter has been impressive.

Circle No. 34 on Readers' Service Card

122 A

·

ANALYTICAL CHEMISTRY

Circle No. 168 on Readers' Service Card