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"For Scientists Everywhere"
BURRELL
UNIFORM SOLUTIONS For G a s Analysis always fresh and active . . . order as you need Modern Burrell Reagents and Auxiliary Solutions are available as a regular, dependable source of supply for use with all makes of gas analysis equipment. Listed here are some perennial "best sellers." Tell us your needs for prompt service.
Fast Absorbing Reagents COSORBENT© for Carbon Monoxide. Active and accurate. Forms stable compound. Requires few passes. CAT. No. 3 9 - 7 2 0 - 8 oz. 6.60 CAT. No. 39-721 - 3 oz. 3.60
Case of 1 2 - 7 1 . 3 0 Case of 1 2 - 3 8 . 6 5
COSORBENT POWDER for Carbon Monoxide. Easier to store and transport. Has indefinite shelf life. CAT. No. 39-72S—vial 3.85
Case of 12 vials—41.60
LUSORBENT© for Unsaturated Hydrocarbons. N o vapor pressure. Non-Corrosive to rubber connections. CAT. No. 3 9 - 7 1 5 - 8 oz. 5.00
Case of 1 2 - 5 0 . 0 0
OXSORBENT® for Oxygen. Fast, clean and accurate. Breaks sharply at saturation point. CAT. No. 3 9 - 7 1 0 - 8 oz. 6.00 CAT. No. 39-711—3 oz. 3.25
Case of 1 2 - 6 4 . 8 0 Case of 12 — 35.10
DISORBENT© for Carbon Dioxide. Crystal clear potassium hydroxide solution. Accurate and fast. CAT. No. 3 9 - 7 3 0 - 1 6 oz. 3.60 CAT. No, 39 731—3 oz. 2.10
Case of 1 2 - 3 8 . 6 5 Case of 1 2 - 2 2 . 6 0
© T r a d e m a r k Registered U.S. Patent Office
©Trademark
NOTE: Order 8 oz. for each charge in a standard a b sorption pipette; 3 oz. for Industro® gas analyzers.
S p e c i f i c s for H y d r o c a r b o n s SORBENT "A"@—For total olefins, ethene, propene, butène and pentenes. CAT. No. 39-741 - 8 oz. 6.75 Case of 12-67.50 SORBENT "B"©-For selective absorption of iso-butene. Takes up 1-butène and 2-butene slowly. CAT. No. 3 9 - 7 4 2 - 8 oz. 3.75
Case of 12—37.50
SORBENT "C"©-For propenes, butènes and pentenes. Will absorb ethene slowly. CAT. No. 3 9 - 7 4 3 - 8 oz. 3.75
Case of 12—37.50
©Trademark Prices listed a r e F. Ο . Β. Pittsburgh, Pa.
Ask for Bulletin No. 327
BURRELL CORPORATION Scientific Apparatus and Laboratory Supplies 2 2 2 3 FIFTH AVENUE, PITTSBURGH 19, PA.J Circle No. 22 on Readers' Service Card
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ANALYTICAL CHEMISTRY
is t h e only reagent which will permit the direct identification of benzene or toluene sulfonic acids. T h e basic technique is t o precipitate t h e salts a n d take melting points. M a n y common multifunctional acids as well as sulfonic acids m a y be identified this way. D r . Affsprung also described uses of some other n e w reagents. D i - n octyl sulfoxide, soluble in nonpolar solvents, can b e used t o extract acids into carbon tetrachloride a n d cyclohexane. I t also h a s been used, for example, t o determine gold in t h e presence of large a m o u n t s of iron and small amounts of platinium. o-Aminothiophenol forms a reversible organic electrode sensitive t o h y drogen ion. T h e reagent is useful as an indicating electrode for acid-base titrations. I n addition, t h e thiol will precipitate a n d complex various metal ions, making it useful for potentiometric titrations. Besides its volumetric uses, t h e reagent can b e used gravimetrically as a precipitant. Chromatography. T h e main advantage of programmed t e m p e r a t u r e gas c h r o m a t o g r a p h y ( P T G C ) is speed, said D r . Stephen D a l Nogare of E . I . du P o n t de Nemours. T h e time reduction achieved b y P T G C m a y b e seen b y comparing t h e linear correlation of carbon n u m b e r and liquid phase polarity with corresponding logarithmic relations for isothermal conditions. T h e best mode of operation based on m a x i m u m efficiency a n d resolution involves slow heating rates in t h e range of 5° to 10° C. per m i n u t e with conventional liquid phase column loadings of about 2 0 % , D r . D a l Nogare said. Decreasing t h e starting t e m p e r a t u r e always improves resolution. S u b ambient temperature programming promises to extend t h e usefulness of PTGC. Limiting efficiencies can b e derived and used t o define t h e critical aspects of lean a n d rich columns in t h e performance of isothermal columns. A lean column (liquid phase a b o u t 1%) is selected for speed and a rich column, for resolution. D r . D a l Nogare showed how a resolution equation containing t h e column characteristic (β, t h e ratio of gas t o liquid volume) serves to relate such extremes in columns as capillary and packed. A performance criterion states t h a t βάν = 0.5, where dv is t h e particle diameter of t h e packing. This equa tion permits a n estimate of t h e opti m u m fraction of liquid phases for a n y particle diameter for a typical diatomaceous support. T h e criterion re quires higher liquid phase loadings for large particles (small β) a n d suggests
