A C BRIEFS
MICROSCOPE 'EM SLIDE LABELS
TIME
Rapid Determination of Diphenylhydantoin in Blood Plasma by Gas-Liquid Chromatography
for futtr. ι
Diphenylhydantoin is extracted from buffered plasma with toluene containing methylphenylphenylhydantoin. Both hydantoins are then extracted into methanolic tetramethylammonium hydroxide, followed b y methylation, a n d gas chromatographic determination. JOSEPH MacGEE, Medical Research Laboratories, Veter ans Administration Hospital, 3200 Vine Street, Cincinnati, Ohio 45220, and the Departments of Biological Chemistry and Internal Medicine, College of Medicine, University of Cincinnati, Cincinnati, Ohio Anal. Chem., 42, 421 (1970)
A New Technique for the Determination of Picloram and Other Herbicides Containing Carboxylic Acid and Ester Groups On column decarboxylation of Picloram (4-ammo-3,5,6trichloropicolinic acid) provides a sensitive and superior gas-chromatographic method for determining this herb icide in water, soil, or forage samples. R. C. HALL and C. S. GIAM, Department of Chemistry, Texas A&M University, College Station, Texas 77843 and M. G. MERKLE, Department of Soil and Crop Science, Texas A&M University, College Station, Texas 77843 Anal. Chem., 42, 423
(1970)
«teritlfteatien
m^-r^m^ Permanent, pressure-sensitive TIME Slide label sticks to the slide with just a touch of the fingers . . . won't curl up or c o m e loose. Mark them with ball point pen, pencil, typewriter. 7/β" χ Va" Slide Labels and % " χ % " End Labels are available in standard or tissuehigh thickness, in roll or sheet f o r m . Also available color-tinted to your specifications. Use them plain or imprinted with your de partment name. Economical TIME Slide Labels increase laboratory efficiency. FREE B R O C H U R E ! Write for samples, illustrated bro chure, and the name of a dealer near you.
PROFESSIONAL 363
EAST
BURLINGTON
TAPE COMPANY, ROAD.
RIVERSIDE,
INC.
lUUINOIS
60546
Circle No. 44 on Readers' Service Card
Use APIEZON ... Oils, Sealing Compound and Waxes
Correspondence Determination of Carrier-Free Promethium by Ion-Focusing Electrophoresis H. Y. GEE and M. W. NATHANS, Trapelo Division/West, LFE Corp., 2030 Wright Avenue, Richmond, Calif. 94804 Anal. Chem., 42, 425
(1970)
Aids for Analytical Chemists Two-Stage Molecular Separator for Connecting a Gas Chromatograph to a Mass Spectrometer MICHAEL A. GRAYSON and CLARENCE J. WOLF, McDon nell Research Laboratories, McDonnell Douglas Corp., St. Louis, Mo. 63166 Anal. Chem., 42, 426 (1970)
Apiezon Oils have very low vapor pressures and are very stable. They are ideally suited as vapor-diffusion pump fluids. Apiezon Sealing Compound Q is a putty-like sub stance, a relatively low cost, extremely versatile sealing medium. Apiezon Waxes are for vacuum joints of a more permanent nature. Write for BULLETIN 43 AC
Simple Electrode for Thin*Layer Electrochemistry
J A M E S G. B I D D L E
JAMES C. SHEAFFER and DENNIS G. PETERS, Department of Chemistry, Indiana University, Bloomington, Ind. Anal. Chem., 42, 430
(1970)
BIDDLE
812
CO.
Electrical and Speed Measuring Instruments MEETING, PENNSYLVANIA 19462 Phone 215.646-9200
INSTRUMENTS PLYMOUTH
Circle No. 11 on Readers' Service Card ANALYTICAL CHEMISTRY, VOL. 42, NO. 3, MARCH 1970
·
19 A
