Chemicals
Reference Standards
Data System for FT NMR
Source Gas Sampler Model 7340 gas sampler, designed to EPA specifications, can be used for stack sampling of gases. The complete system includes a control module, impinger sample case, heated gas-lined probe, and connecting umbilical cord. The sampler can be used to run EPA methods for water vapor, sulfur dioxide, and nitrogen dioxide. Microchemical Specialties Co. 409
The new NMR-80 data acquisition and processing system for Fourier transform NMR combines the benefits of a hard-wired signal averager and a general purpose computer. Some of the features of the system are a 20-bit word length, 100-nsec timing accuracy, digitizing speeds up to 10 jusec/point, and continuous display and flexible control of experimental variables through keyboard entry. From $20,000. Nicolet Instrument Corp. 410
Ultra-Low Temperature Chamber
Standard solutions of 100 materials which are either carcinogenic, teratogenic, or mutagenic are of the highest purity available (usually 99.5%) and are packaged in concentrations of 10 ppm, with a dilution accuracy of 0.5%. These so-called Nanogen standard solutions are $10/10-ml bottle. A two-page data sheet lists the materials. Duke Standards 427
A kit of asbestos fibers includes prepared slides and sample vials of the five types of asbestos most commonly used in world commerce. About 60% of the fibers are in the respirable and injectable size range. They have been characterized for size data, chemical composition, and optical properties. Duke Standards Co. 428
Electrode A new electrode, the BenchMark, protects the delicate glass pH sensing element. This element is actually a tube within this new style. It is surrounded by two glass outer tubes of much greater strength. The new sensor can be used for regular dip-type measurements or for continuous flow through the hollow center and is a direct replacement of conventional style units on most pH meters. $98. Markson Science, Inc. 422
The Mark II for preparative polyacrylamide gel electrophoresis offers increased resolution. Up to 80 mg of proteins, enzymes, and other compounds of closely related molecular weights and electrophoretic mobilities can be separated rapidly and with discrete separation of the fractions. Shandon Southern Instruments, Inc. 423
Carcinogenic Chemical Standards
Asbestos Fiber Standards
A chamber for vapor traps or baths provides cryogenic temperatures without liquid nitrogen. The chamber has a capacity of 4 liters and operates t o - 1 2 8 ° C . F T S Systems, Inc. 421
Gel Electrophoresis Apparatus
Five reagent grade reference standards for organic chemical analysis are: acetanalide (for C, H, N, and O), l-chloro-2,4-dinitrobenzene (forC, H, CI, N, and O), l-nitroso-2-naphthol (for C, H, N, and O), stearic acid (for C, H, and O), and sulfanilic acid (for C, H, N, O, and S). Several Ultrex microanalytical standards for sulfur, phosphorus, nitrogen, nitrogen (heterocyclic), fluorine, and iodine are also available. J. T. Baker Chemical Co. 426
LC Solvents The first line of solvents specifically designed for high-pressure liquid chromatography has been designated ChromAR solvents and can be used in column and thin-layer chromatography also. These solvents provide uniform low UV absorbance and uniform refractive index, polarity, and viscosity. Mallinckrodt Chemical Works 430
Bioluminescent Detector A bioluminescent vapor detector can be used to detect or monitor various gases with changes in its sensor head. The sensor is a culture of marine bacteria which produce light and can be bred to respond to most gases. By isolation and selection of various strains of these bacteria, the sensitivity and specificity of these organisms can be optimized to a particular gas or odor. Monitek Corp. 411
Silica Adsorbents for LC Three new microparticle silica packings for liquid chromatography are designated PartiSil 5, PartiSil 10, and PartiSil 20. They offer improved performance because of lower pressure drops owing to their physical structure. Their improved organic purity eliminates unknown chromatographic effects, such as peak asymmetry. Reeve Angel 431
ANALYTICAL CHEMISTRY, VOL. 46, NO. 1, JANUARY
1974 · 77 A
