with I

B e c k m a n ® microelectmdes** eliminates nem-wracking uncertainty of visual detection! Now. . . titrate such small quantities as α single drop — easily and accurately — with the Manostat Microtitrator, a modifica­tion of the Gilmont Ultramicroburet. The new Beckman Microelectrodes overcome the limitations of previous methods of titration, where larger quantities were required. And—this Manostat apparatus performs microtitration electrometrically, without need for visual adjustment of the end point.

The Manostat Microtitrator is capable of both oxidation-reduction titration as well as acidimetry-alkalimetry. . . with special electrodes for each process. It may be used with any high-impedance pH meter, such as the Beckman Zeromatic ( s h o w n in p i c t u r e ) . T h e a p p a r a t u s comes fully equipped with all accessories and solutions. Nothing else is needed but your pH meter. Patent applied for.

^-'Manufactured exclusively for Manostat Corp.

FOR M I C R O T I T R A T O R B U L L E T I N

M15654 and all M15655 convert

HOW IT WORKS: Electrometric titration of micro quantities requires a special type of electrode assembly which meets the space requirement. This is accomplished by a combination of the glass electrode membrane and container in one unit, the pH sensitive glass membrane being sealed to the bottom of a small test tuDe. This tube is then inserted into a refer­ence electrode solution contained in a U tube.

To further meet the limitations of reduced space, the buret tip, salt bridge to second reference electrode, and stirring mechanism are all combined in one unit. The buret tip is surrounded by a second glass tube which forms an annular space through which air or an inert gas may be passed to vigorously agitate the solution being titrated. The titrant itself serves as the salt bridge to the reference electrode. Another electrode of similar construction is inserted into the U tube. The flow of current is therefore from this electrode through the reference solution, through the glass membrane to the unknown solution, then to the t i trant and finally to the reference electrode.

Because of the high resistance of the glass membrane to ionic flow, problems of electrical leakage enter when the glass electrode is separated into two containers. To reduce this leakage, all glass parts of the electrode are treated with a hydrophobic coating of silicone.

MANOSTAT MICROTITRATOR, complete with Beckman Microelectrodes accessories, but without pH meter 245.00 MICROTITRATOR ACCESSORY KIT contains all equipment necessary to a Gilmont Ultramicroburet to M15654 128.50

The EMIL GREINER Co. S® 2 0 - 2 6 N . M O O R E STREET DEPT. 221 A , N . Y . 1 3 , Ν . Υ .

Circle No. 17 A on Readers' Service Card

VOL. 3 1 , N O . 4 , APRIL 1 9 5 9 · 3 A

NOW! DETECT END POINT ELECTROMETRICALLY!