Flow feedback makes the first

master LC

Here's a gradient elution chromatogram with eight times the sensitivity you usu­ally see. Flow feedback control has elimi­nated pump noise, which is ordinarily a serious problem in gradient chromatogra­phy at high sensitivities. The baseline noise you see is the inherent low noise of the UV detector.

Column: 2.1mm diameter χ 150mm Lichrosorb adsorbent, ΙΟμιη

Solvents: A- isooctane, B- isooctane, methy­lene chloride, chloroform, methanol: 80, IS, 3, 2

Program: 1% to 40% Β at 4% per minute Flow rate: 3.6 ml/min. at 1500 psi Sample: 25 μΐ spiked food extract Attenuation: 2x (.02A full scale) Analysis time: 9 minutes

Here's the first liquid chromatograph to combine unsurpassed sensitivity for analytical work with unlimited solvent volume for preparative work. It's done with flow feedback control, a unique means of obtaining a pulseless flow from a reciprocating, continuous-flow metering pump.

The pulseless flow increases sensitivity by reducing noise in analytical work—especially in gradient elution, which can now be done with unprecedented sensitivity.

The continuous flow enables you to do preparative work with any volume of solvent flowing as long as you require.

Only Chromatronix Model 3500 LCs have flow feedback control, consequently, they're the only LCs

that can do high-volume preparative work as well as ultra-sensitive analytical work.

Model 3500 operates at pressures up to 7000 psi and comes in isochratic and gradient models with and without a column oven. Be sure to check out the unique capabilities of this chromatograph before you buy any other LC.

For more information on Model 3500 contact Chromatronix Division, Spectra Physics, 2743 Ninth Street, Berkeley, Calif. 94710. Phone (415) 841-7221. Or phone our nearest regional office: Stirling, N.J. (201) 647-5890. Houston (713) 864-6128. Chicago (312) 541-3800. In Europe we're at 6100 Darmstadt, Alsfelder Strasse 12. (06151) 75081.

Spectra-Physics

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