NEW CHEMICALS Collidine Buffer Kit
The anxiety remover. Without you knowing, the new Tempunit adjusts an overheat cutout to trip at 3°C above any operating temperature you select.
Sym-collidine ( 2,4,6-trimethylpy ridine) with hydrochloric acid is a newly available stable buffer system for regulating the pH of biological fixative solutions. This new product is rigorously purified by triple urea-canal complex crystallization and careful fractionation. Polysciences, Inc., Warrington, Pa. 18976. 215-343-6484 501 Custom Standard Solutions for Atomic Absorption
Now available is a personalized service for analysts. Any of 62 elements may be prepared in a choice of matrix and concentration from 1000 to 10,000 ppm. A minimum order of fine 100-ml bottles of each custom standard is required. Solutions may be aqueous or in a matrix of the customer's choice. F & J Scientific, 79 Far Horizon Dr., Monroe, Conn. 064GS. 203-268-3335 502
Tempunit® Model TU-12 Constant temperature circulator Also ·
low water level cutout · time proportioning control to ± 0.01°C
• zero voltage s w i t c h i n g · s e p a r a t e i n d i c a t i n g a n d s e t t i n g p o i n t e r s · powerf u l c i r c u l a t i n g p u m p · s t a i n l e s s steel c o n s t r u c t i o n · new large clear scale See the latest Tempunit*.
1,2 Propylenediaminetetraacetic Acid
This analog of EDTA is now offered as the first in a series of unusual polyammo carboxylic acid chelating agents produced under a new long-range synthesis program. Information on this program and data and a bibliography sheet on 1,2 PDTA are available. LaMont Laboratories, P.O. Box 30632, Dallas, Tex. 75230. 214-231-0218 503
* The original portable water bath controller—over 30,000 sold! Circle No. 119 on Readers' Service Card
TRI-SIL - A Reagent-CatalystSolvent formulation for preparing Trimethylsilyl derivatives of polar compounds under mild conditions. Smooth. . .Positive. . . Broadly Useful. No. 48999 TRI-SIL $16/50 ml
Ultrahigh Purity Reagents
A group of ultrahigh purity reagents for the trace element analysis of lunar material has been developed. Ultrex reagents currently available include phosphorus pentoxide and perchloric, sulfuric, and hydrofluoric acids. The impurity level is, in some cases, less than 1 ppb; levels of trace impurities are reported to be below 0.1 ppb for certain elements. Another Ultrex product group is the clinical laboratory standard line. Fourteen primary and secondary standards have been developed. J. T. Baker Chemical Co., Phillipsburg, N. J. 0S865. 201-859-2151 504
NEARLY EVERY GAS CHROMATOGRAPHER Can Use These 3 Proven Aids To Advantage. . . .And A Lot Of Them Do! B S A — One of the most powerful silylating agents known. . . . and ours is the world's finest. No. 38837 BSA $9/25g
Chromatography Solvents
A new large selected list of solvents for use in chromatography and in other physical measurements where purity of the solvent is important is available. Included are 44 chromatography solvents, 49 technical grade solvents, and a Karl Fischer reagent diluent, in 1-gal and 5-gal lots. Further information on
Write to Techne Inc., 661 Princeton Pike Princeton, N. J. 08540 or call (609)452-9275
Ask For FREE "Silylation Handbook"
• S i l y l - 8 - GLC Column Conditioner. Stabilizes errant columns in a few minutes. Just shoot directly into the chromatograph. No. 38014 Silyl-8 $8/25ml vial or $10 for 12x1 ml vials PIERCE CHEMICAL COMPANY P. O. Box 117 Rockford, Illinois 61105 PHONE 615/968-0747
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TWX g l Q - $ 3 1 -3d,19J
Circle No. 40 on Readers' Service Card A N A L Y T I C A L CHEMISTRY, VOL. 4 2 , N O . 3 , M A R C H 1 9 7 0
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