INSTRUMENTATION
ILLCO-WAY
methylsilane resonance line is directly over the zero chart position.
ionXchange
R-F Transmitter. T h e radio-fre quency t r a n s m i t t e r is crystal-stabilized at an o u t p u t frequency of 60 mc. This frequency is controlled over a narrow
range by a direct current voltage de rived from the II0 field modulation cir cuit through a frequency discriminating detector. By applying this voltage t o a Varicap (a semiconductor device t h e capacitance of which is a function of applied direct current voltage), t h e
LABORATORY SIZE CARTRIDGE DE-IONIZER GIVES nutwtdfiwL WATER
The ILLCO-WAY Throw-Away Cartridge De-Ionizer consists of a clear plastic column containing mixed-bed ionXchange resins. The mixed-bed ionXchange process will re move all dissolved solids (including, in our Research Model, silica and CO2) so that the effluent is pure enough for the finest analytical purposes. The Cartridge is used also to reduce the interfering ions often found in distilled water. The column is clamped in a bracket, as shown, with tubing and valves to connect to any tap or other water supply. ILLCO-WAY Resins used contain a color indicator which changes from purple to yellow as the resins become exhausted, showing when a fresh Cartridge is needed.
RESEARCH MODEL Removes all ionizable solids including silica and CO2. Average in effluent less than 0.5 ppm. total solids. Capacity, 450 grains as CaC03. Flow Rate, 5 gph. max. Price, 112.50 Bracket, extra, $7.50
UNIVERSAL MODEL Removes all ionizable solids, except silica and COa.Suitableforgeneral pure water needs, .. .__ Λ Capacity, 900 grains as CaCOa. p | o w R a te, 5 gph max. p r j c e i jg 75 Bracket, extra, $7.50
Order from your Laboratory Supply House or Write to . . .
ILLINOIS WATER TREATMENT CO. 8 4 0 Cedar Si. Rockford,
III.
NEW YORK OFFICE: 141 E. 44th SI., N e w York 17, N.Y. C A N A D I A N DIST.: Pumps & Softeners, Ltd., London, C a n .
Figure 4. Proton counting. Using the integrated spectrum of the sample (upper curve), the lowest common divisor for the integrals of the various re solved groups of protons is found by a simple arithmetic procedure. This represents an integral number, n, of protons. We can then determine the num ber of times this divisor goes into the integral of each group and obtain a sum which is the total number of protons in the molecule divided by n. If we can assign correctly the number of protons in a group on the basis of its position, line shape, or spin coupling, we may be able to determine η without further data. If not, an approximate molecular weight and percentage of hydrogen will serve to fix n. The molecule prodigiosin is believed to have the structure shown. Since it gives methyl amyl pyrrole upon degradation, there is little doubt that the peak at 238 c.p.s. represents the 3 protons of a methyl group. The integrals then take on integer values which add up to 25, the number of protons in the molecule
Figure 5. Analysis of reaction mixtures. The conversion of 2-t-butyl-5-methyl cyclohexanone into its enol acetate results in an inseparable mixture of A and Β which resists even vapor phase chromatographic methods. The analysis of this mixture cannot be accomplished by optical spectroscopic means and presents a formidable problem to the chemist, requiring a lengthy degradative approach. High resolution NMR provides an immediate and accurate analysis, using a few milligrams of material which are easily recovered. The strict proportionality of signal integrated intensity to the number of nuclei contributing allows the in tegral, a, of the peak at 316 c.p.s. to serve as a measure of the amount of B, containing one olefinic proton per molecule. The total integral b, divided by the number of protons (22) gives the integral per proton and the ratio 22 a/b the percent of Β directly. The analysis gives 46 percent Β in the mixture
Circle No. 50 on Readers' Service Card
106 A
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ANALYTICAL CHEMISTRY
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