REPORT FOR ANALYTICAL CHEMISTS
Look at What this tubing offers: •
sfays flexible a n d t o u g h e v e n a t m i n u s 4 5 0 ° F or higher t h a n 5 0 0 ° F
« unaffected b y a n y c o m m e r c i a l solv e n t to p r o v i d e v e r y long life •
easily c l e a n e d a n d sterilized b e c a u s e of its s m o o t h , chemical resistant surface
•
its translucency
s h o w s fluid
Look of the extra builds into it:
flow
reliability
PF
controls, but also produced data that aided in substantial increases in product yields. Fundamental information obtained from this work was proof that organophosphorus mixtures such as these were not being chlorinated by molecular chlorine, but rather by chlorine in the form of phosphorus pentachloride. The simple apparatus designed for laboratory chlorine demand is shown in Figure 1; the typical curve, in Figure 2. A not too dissimilar system was developed for the fluorine demand of organophosphorus mixtures. In this procedure unreacted hydrogen fluoride is titrated as ionic fluorine in a non-aqueous medium. The foregoing discussion cites a few of the direct contributions of analytical research to organic synthesis and process engineering. With present-day spectrophotometric capabilities, and even more so with gas liquid chromatography, the analytical horizon has broadened. These instrumental techniques would not have directly solved the chlorine or fluorine demand requirement; however, by combining instrumental with chemical techniques the laborious distillations and other separations that were employed to prove the de-
veloped methods would not have been necessary. Trace Analytical
Techniques
Another very important problem of the analytical chemist in CBR is the development of methods for the estimation of trace quantities of biologically active material. Owing to the high effectiveness of some of these compounds at very low dose, measurements must be accurate in the range of 10 - Vg. and higher. Systems must be designed for the collection and determination of vapor or aerosol in air or when impacted in water or earth. Bubblers containing solvent are effective for vapors, and filters or impactors are effective for aerosols in air. Active compounds or their residues are determined directly in water or as in the case of earth, after extraction with a suitable solvent. Wherever possible, methods are sought which could allow the continuous monitoring of air. In keeping with the attempt to illustrate a problem with examples, the phosphorus anticholinesterases will again be cited here. The methods to be discussed were developed for Sarin and its homologs, Tabun, DFP, T E P P and its homologs, and ester pyrophosphonates. The per-
• tight t o l e r a n c e control a n d consistent u n i f o r m i t y DRY ICE-ACETONE OR C H L O R O F O R M COLD FINGER
• a tensile strength greater t h a n 3 0 0 0 psi a n d a n e l o n g a t i o n greater t h a n 200%
ALL FLEXIBLE T U B I N G IS TYGON
• d e v o i d of f l a w s a n d impurities .. is scrupulously inspected a n d 1 0 0 % proof pressure tested . . . y o u r g u a r a n t e e of a high q u a l i t y product Let PENNSYLVANIA FLUOROCARBON fill your requirements for flexible tubing of Teflon and you can be sure of getting what you p a y for. This tubing is widely used for acid, solvent or catalyst lines; for sampling tubes, laboratory tubing, fuel and hydraulic lines; for f o o d , pharmaceutical and medical tubing where the unique properties of Teflon and the extreme reliability of PF extrusions apply. Let us bid on your requirements for flexible tubing of Teflon tailored to meet your size, color and application needs. Flare, insert and ferrule type fittings can be used with this PF tubing.
C H L O R I N E BOTTLE 5 0 0 G. CAP.
GLASS OR R U B B E R STOPPER
DRYING TUBE
N I C H R O M E HEATING ELEMENT (VAR1AC CONTROLLED)
Figure 1 . Circle No. 94 on Readers' Service Card 32 A
•
ANALYTICAL CHEMISTRY
* I M P E D A N C E BRIDGE OR VOLTAGE DOUBLER RECTIFIER A N D M I L L I A M METER, OR BRIDGE A N D RECORDER
Laboratory Conductivity End-Point Apparatus K = 2.72 o h m s 1
