a
Improve your
DRUMMOND "MICROCAPS"
Gas-Chromatography with
new tool for the Chemist
(Disposable micro-pipettes) These p i p e t t e s consist o f short lengths of
precision
brated
GAS-CHROM
to
capillary
contain
from end to end.
a
tubing,
definite
They a r e
cali
volume accurate
t o w i t h i n less t h a n 1 % a n d a r e so l o w in cost t h a t y o u c a n a f f o r d t o use t h e m once a n d d i s c a r d t h e m . W h i l e t h e y a r e o f g r e a t v a l u e in g e n e r a l micro-chemical a p p l i c a t i o n s , t h e y are
Column Packing Obtain Support
Low percent fines Better separation
* Pure white powder
Short conditioning time
* Various mesh sizes from 60/80 to 140/200
Long life Reduced tailing Active sites controlled Pretested before shipment It always works when you try it.
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Time! Money!
PRICES per half pound bottle of GAS-CHROM 60/80 Mesh
80/100 Mesh
$23.00
$35.00
$23.00
Acid Washed Gas-Chrom A
30.50
42.50
30.50
Acid & Alcoholic Base Washed Gas-Chrom Ρ
38.00
50.00
38.00
Standard Grade Gas-Chrom S
100/120 Mesh
120/140 Mesh
100/140 Mesh
140/200 Mesh
PHASES—COATINGS—COATED PACKINGS—PACKED also a v a i l a b l e , send for literature
COLUMNS
A P P L I E D SCIENCE L A B O R A T O R I E S , I N C . ( A S I ) 1 4 0 N . B a r n a r d St., S t a t e C o l l e g e , P a . Phone A D 8-2406 Circle No. 200 on Readers' Service Card ·
No
ANALYTICAL CHEMISTRY
of
particular
Operation: The p i p e t t e is inserted t h r o u g h t h e r u b b e r c a p on the e n d o f the b u l b a s s e m b l y shown a t the l e f t . A hole in t h e e n d o f the r u b b e r b u l b permits filling b y c a p i l lary attraction. When filled from end to e n d , the v o l u m e is c o r r e c t — no m o r e , no less. To discharge: hold finger o v e r the h o l e in e n d o f bulb and squeeze. To rinse, r e p e a t the o p e r a tion with the diluent. M i c r o c a p s a r e s t o c k e d in the f o l l o w i n g sizes: 1, 2 , 3 , 4 , 5 , 10, 1 5 , 2 0 , 3 0 , 40, 5 0 , 75 and 100 l a m b d a . O t h e r sizes c a n b e m a d e u p o n short notice. Prices: 1 t o 5 0 l a m b d a incl., p e r v i a l o f 100 (with bulb assembly) $ 4 . 5 0 ; over 5 0 to 1 0 0 lambda, per 100, $5.50. PRECISION CAPILLARY
Please specify grade (S, A, P) a n d m e s h w h e n o r d e r i n g . For high e f f i c i e n c y t r y 140/200. For general use we r e c o m m e n d Gas-Chrom A on 100/140 m e s h . For Steroids use Gas-Chrom P. To cover a variety of needs order Trial T e s t Kit, 25 g r a m s each of any 6 k i n d s (you select grade a n d m e s h ) $27. We also sell Johns-Manville CHROMOSORB all grades, s t a n d a r d p r i c e s . Ail prices F.O.B., State College, Pa.
134 A
in h a n d l i n g
skill is n e e d e d in o r d e r t o o b t a i n a c
* Flux calcined diatomaceous earth
Low bleed rates
useful
material.
c u r a t e results.
Faster flow
Shorter retention time
especially
dangerous
TUBING
W e c a n also furnish c a p i l l a r y t u b i n g t o a t o l e r a n c e o f plus o r minus . 0 0 5 m m , o f a n y d i a m e t e r u p t o 1.5mm O . D . , in 1 2 o r 2 4 " lengths. This t u b i n g m a y b e h a d in s t a n d a r d flint, l e a d , or boro-silicate glass. Write for further information.
DRUMMOND SCIENTIFIC CO. 5 2 4 - 5 2 6 N. 61st St. P h i l a d e l p h i a 5 1 , Pa. Circle No. 167 on Readers' Service Card