NEW PRODUCTS 3,4-Dinitrobenzoic acid (NO s ) 2 C 6 H 3 COOH
Trimethylphenylammonium zenesulfonate (pract.) C 6 H 6 N(CH 3 ) 3 OS0 2 C 6 H 6
1, l-Diphenyl-2-thiourea (C 6 H 6 ) 2 NCSNH 2
6
Automatic Program Control
E t h y l phenylundecanoate CJIIOCIOH^QCOO^HS
p-Hydroxyvalerophenone HOC«H4CO(CH 2 ),CH 3 1,2,3,4 - T e t r a h y d r o - 6 - methoxyquinoline CH3OC6H3NHCH2CH2CH2 ι ι
An automatic program control, which permits repetition of a spectral scan a t predetermined intervals over a 24-hour period, h a s been developed b y Applied Physics Corp. No attention of a n operator is needed, according to t h e company. T h e control can be used with Cary spectrophotometers to follow
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TUBING •
NON-TOXIC NON-CONTAMINATING
the course of reactions, in reaction rate studies, in continuous analysis of flow ing samples, a n d in analysis of chro matographic effluents. Added usage is gained through setting u p t h e program control for automatic operation during the night. I n using t h e program control, t h e w-ave-length limits of t h e region to be scanned are set into t h e panel controls on t h e spectrophotometer, a n d time intervals are set into t h e control unit. Other conditions of t h e analysis a r e set upon t h e spectrophotometer in t h e usual manner. T h e spectrophotometer then automatically scans between t h e limits set, returning after each scan t o the starting conditions in readiness for the next scan. Spectra appear in se quence on t h e recorder chart paper. 7 Laboratory Clamp A new laboratory clamp using a band of spring steel as t h e clamping device is being marketed b y I t . I . Mendels, I n c . T h e b a n d allows t h e clamping pressure to be distributed around t h e entire circumference of t h e glassware, thereby reducing breakage.
EASY TO HANDLE NON-KINKING SMOOTH A N D SEAMLESS EASY TO COUPLE A N D UNCOUPLE
Tough, flexible, chemically inert Tygon is the logical choice to safely handle every laboratory tubing application. I t couples easily, won't kink or collapse. Glass-like clarity provides ins t a n t visual inspection. All required sizes are stocked by laboratory supply houses everywhere.
T h e clamp is available in three sizes: T y p e A, for glassware 1 t o 2 inches in diameter; T y p e B , 2 t o 3 inches; and T y p e C, 3 to 6 inches. 8 N e w Primary Standard T h e seventh primary standard, cal cium carbonate A R , has been added t o the Mallincrodt Chemical Works' line of analytical reagents. This standard was developed to serve t h e analytical re quirements of flame photometry and Versene titrations. 9 Power Supply
FLASTICS and SYNTHETICS
DIVISION
U. S. STONEWARE Akron 9 , Ohio
For further information, circle number 66 A on Readers' Service Card, page 61 A
A new high voltage power supply mar keted b y H a m n e r Electronics Co., Inc., is said t o provide t h e high degree of sta bility previously available only with batteries. T h e stability is limited only b y t h e voltage reference tubes, which are t h e new ultrastable 85A2 types operated under constant pressure. T h e voltage variation of these tubes is less For further information, see coupon on page 61 A ANALYTICAL
CHEMISTRY
