Techne Incorporated

Why indeed! Techne baths offer a remarkable performance for an extraordinary low cost. High quality stainless steel tanks using solid drawn constructi...
1 downloads 0 Views 280KB Size
THE PARR® ACID DIGESTION BOMB The

rapid

a n d safe

way to

Table I I I . Typical Computer Search Results

Sample y-Nonalactone

HF,

HC1 o r organic

strong

alkalis

acids

with

HNOs,

^7.1 95.1 95.0 94.4

l,4-Dichlorobutene-2 3,4-Dichlorobutene-l l,2-Dichlorobutene-3 l,4-Dichlorobutene-2

Pregna-4,6-dien-20a-ol3-one

100.0

Pregna-4,6-dien-20aol-3-one 16-Methyl-16-dehydropregnenolone 16-Dehydropregnenolone acetate Dihydrogedunin

or to

materials or

in

oxidizing

complete

sample

87.1

recovery.

86.8 85.6 Samples a r e held i n a 2 5 m l , t h i c k walled T e f l o n * c u p w h i c h is n o t attacked b y t h e acid charge. This c u p is c o n f i n e d w i t h i n a sturdy stainless steel b o m b f r o m w h i c h i t is easily removed f o r sample recovery a n d w a s h i n g . No wrenches o r clamps are needed t o p r o d u c e a t i g h t seal. Ask for PARR Bulletin 4745 describing this rapid method for dissolving difficult samples.

^Λ_ "^'

2,6-Di-r-butyl-4-methylp h e n o l (ionol)

COMPANY

211 F i f t y - T h i r d St.

M o l i n e , I I I . 61265 (309)

85.5

Water baths At these prices why buy an ordinary bath? Why indeed! Techne baths offer a remarkable performance for an extraordinary low cost. High quality stainless steel tanks using solid drawn construction. Available in five standard sizes. Using thermistor temperature sensor and all solid state switching. Control ± 0 . 0 5 ° C. Range 0 to 1 0 0 ° C or 2 0 0 ° C. These are stirred baths, available w i t h optional pump for circulation to external apparatus. A shaking water bath and a complete range of accessories are also available. Prices start as l o w as $215.00. For free 16 page constant temperature bath catalog write t o Techne Incorporated. 6 6 1 Brunswick Pike. Princeton. N e w Jersey 0 8 5 4 0 or call (609) 4 5 2 - 9 2 7 5 .

Techne . . . leaders constant baths.

in temperature

A V A I L A B L E T H R O U G H M A J O R LABORATORY SUPPLY HOUSES.

CIRCLE 2 2 3 O N READER SERVICE CARD 744 A

ANALYTICAL

C H E M I S T R Y , V O L . 4 6 , N O . 8, JULY 1974

2,6-Di- f -butyl-4m ethyl-phenol 2,6-Di-f-butyl-phenol 2,6-Di-f-butyl-4methyl-phenol p-f-Butylphenol

1-Pentadecene

100.0 99.5 99.1 98.8

1-Pentadecene 1-Heptadecene 1-Octadecene 1-Octadecene

o-Tolyl-p-tolylether

100.0 93.3 93.2 91.8

o-Tolyl-p-tolylether m-Tolyl-p-tolylether Phenyl-o-tolylether Di-p-tolylether

97.1 96.8 96.7 96.6

4-Octyne 4-Octyne 4-Nonyne 4-Methyl-2-hexyne

3-Nonyne

762-7716

CIRCLE 1 8 9 O N READER SERVICE CARD

93.5 89.5 88.3

*duPont TFE flurocarbon resin.

PARR INSTRUMENT

Reference compound 7-Nonalactone 7-Decalactone 7-Octalactone 7-Heptalactone

l,4-Dichlorobutene-2

dissolve inorganic samples i n digest

Similarity, % 100.0 96.5 94.2 94.1

o-Chloropropylbenzene

100.0 99.5 94.3 93.6

Diamylamine

100.0 96.6 95.6 95.2

o-Chloropropylbenzene m- a n d p-Chloropropylbenzene p-Chloroethylbenzene o-Chloroethylbenzene Diamylamine Di-(2-ethylbutyl)amine Di-isohexylamine Di-(l-methylheptyl)-

Nevertheless, if much additional nonspectroscopic in­ formation about the sample is available, a human analyst is generally much more powerful than a machine. There­ fore, systems in which computer-aided interpretation of spectral data is used to identify the structure of organic compounds will find their main application in fields where samples have to be routinely analyzed without knowledge of their origin, e.g., in the fields of forensic chemistry, analysis of metabolites, and environmental pollution.

Bibliography J. T . Clerc, F. Erni, C. Jost, J. Meili, P . Naegeli, and R. Schwarzenbach, Z. Anal Chem., 264, 192 (1973). S.L. Grotch, Areai. Chem., 45,2(1973). S. R. Heller, ibid., 44,1951 (1972), H. S. Hertz, R. A. Hites, and K. Biemann, ibid., 43, 681 (1971). Kain-Sze Kwok, R. Venkataraghavan, and F. W. McLaff'erty, J. Amer. Chem. Soc, 95, 4185 (1973). B. A. Knock, I. C. Smith, D. E. Wright, R. G. Ridley, and W. Kelly, Anal. Chem., 42, 1516(1970). L. E. Wangen, W. S. Woodward, and T. L. Isenhour, ibid., 43, 1605(1971).