PRESSURE

are RETTER

• LEAKTIGHT to 250 psi

• NO COLD FLOW LEAKAGE

• NO DEAD VOLUME

• FRONT VALVE for storage

• REAR PLUNGER STOP

• INTERCHANGEABLE PARTS

^ PRECISION SAMPLING

C O R P O R A T I O N

P. O. BOX 15119 • BATON ROUGE, LOUISIANA 70815

Send me more i n f o rma t i on on why Pressure-Lol: gas syringes are be t te r .

NAME

T ITLE

C O M P A N Y -

AODRESS_

CITY

A C S L a b G u i d e See ad , page 2 4 7 Circle No. 142 on Readers' Service Card

New Products

circuit that holds and displays photo­metric values at the optimum time. Single- and triple-pass optics are also offered. Model 440 is a single-beam instrument and offers the major fea­tures of Model 444. Model 448 is de­signed to fit limited budgets. Concen­tration is presented directly on a meter and the instrument is designed with single-pass coated optics. The burn­ers featured in the spectrophotometers are Model 405, the Autolam, and the Autolam-S. Beckman Instruments, Inc., 2500 Harbor Blvd., Fullerton, Calif. 92034 413

A Protein Sequenator incorporates solid state program control to provide error-free sequencing in accordance with the Edman Method. The system selected can be either fully automatic using the program board or completely manual. The instrument can be set for single-cycle operation or an auto-reset cycle can be set after any stage number. An internal control system constantly mon­itors key functions, and 41 projected readout or indicator lights continuously display the function being performed by the Sequenator. Additional features are 40 independent stages individually ad­justable from 0.05 to 50 minutes in 0.05 minute increments and 20 output func­tions. Illitron, 2501 N. Keeler Ave., Chicago, III. 60639 414

Specific Ion Meter

Model 407 is capable of direct read­out of total concentration as well as ionic concentration and activity, pi J, and millivolts. The 407 has a special scale that makes possible 2-minute to­tal concentration measurements as pre­cise as measurements using titration or colorimetric methods. A small known volume of a concentrated solution is added to an unknown and the initial concentration of the unknown is then read directly on the special 407 scale. No computation is required. The re­agent added mav be either a solution

FROM COLEMAN... NEW

LOW TEMPERATURE R-F REACTOR

Removes organic matter without loss of volatile elements

MODEL 40

LOW TEMPERATURE

R-F REACTOR

Clean, dry, low-temperature R-F ash ng w i th Model 40 is far supe­rior to we t and muff le furnace a s h i n g —i t 's the ideal w a y to prepare sampies for e lementa l analysis, air pol lut ion tests and microscopy without alteration of mineral or physical structure. Other appl icat ions include radio-c h e m i s t r y , a u t o r a d i o g r a p h y , r e a c t i o n c h e m i s t r y , a l t e r i n g mo lecu la r s t ruc tu re of p las t ic s u r f a c e s , p l a s m a c h e m i s t r y , removal of photoresist. Request Bulletin A-322.

Write to Coleman Instruments, Division of The Perkin-Elmer Corporation, 42 Madison St., Maywood, Illinois 60153

PERKIN-ELMER

Circle No. 23 on Readers' Service Card

108 A • ANALYTICAL CHEMISTRY

Lllh

NO. 306O0I-A VOL. 1 CC.

S36.00