REPORT
Fast, \ MOLECULAR Accurate W WE|GHT /DETERMINATIONS f
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'
wirtith· Mtchrolab MODEL 301 Otftrtftieter
• operates by ropor-pretiure lowering — aqueout and non- aquêout tolufloni * accural* determination» wllhln 3 minute·
* simple operation—no training needed Sample Slit: a few tenths of a milliliter Temperature Control.· better than 0.001 ° C •reelilom température difference of 0.01 ° C, read to better than I % for deteRed InformaH»» oantdct yoer dealer or wrftei
Mechrolab, Inc.
l O t l LINDA VISTA A V I N U t MOUNTAIN VIEW 1, CALIFORNIA Circle H*. 121 el Kilters' Strtict Cut
PUT HIGH FREQUENCE SOUND
MODEL SG-2
TO WORK IN YOUR ΙΛΒ
*495°°
PRICE
with BLACKSTONE Ultrasonic Systems A simple inexpensive, complete and compact system with 1, 2 or 3 gallon tanks available. This heavy duty, high quality unit is based on an exclusive patented magnorestrictive design operating in the 20 K C range to produce large cavitation bubbles having great useful energy. Ruggedly built for everyday lab use. Nothing to fracture or fatigue. Overheating of low temperature solu tions is minimized and it works efficiently u p to 400° F. when required. Our customers are regularly reporting new and useful applications for the SG-2. From knowledge of these special applica tions, we can help you with your problems. Write us—our facilities are at your dis posal.
CHICAGO
IN JUST SECONDS IT CAN
• Dissolve slightly soluble salts. • Clean intricate glassware, delicate instruments and metallographic specimens.
• Blend solutions • Accelerate organic reactions. • Produce emulsions. • De-gas liquids. • Speed liquid impregnating. • Accelerate electroplating. • Decontaminate.
APPARATUS
COMPANY
KANSAS e m r — I B ! « Μ · » SU K m OU t. Mbsesri · ST.lOUIS-SmBrowAr^Stleefcl^Mtawrl Circle No. 118 on Readers' Service C a r d •
ANALYTICAL CHEMISTRY
, / „ D„ . 1 + 6fe + life' »„r„» , du = ^ 2 - + 24 ( 1 + fe), S7 +
e(ik+kyV^)dx'
1735 North Ashland Avenue, Chicago 22, Illinois
2 6 A
reason and caused much the same revolution. The acclaim would have been great as it has been for other accidental discoveries. B u t to have set out with the aim of proving previously conceived theo retical ideas of the advantages pos sible required a genius and an in sight characteristic of real scientific creativity. Fortunately Golay was not con tent to show merely that a coated tubular column has real practical advantage. He provided the theory to go along with it. In so doing he advanced the theory of the whole field. In his paper at Amsterdam he pointed out t h a t the van Deemter equation lacked a very important dynamic diffusion term. This new term arises from the fact that some molecules spend too much time in rapidly moving eections of the gas while others stay too long in slowly moving portions. I n other words, a term covering the effect of gaseous diffusion perpendicular to the column axis which works to coun teract the fact t h a t the flow varies between the center and the wall of a column. This concept has been very important to the development of the theory of gas chromatog raphy. A comparison of Dr. Golay's Equation 2 for efficiency of open
(2)
tubular columns with the van Deemter Equation 1 for packed columns demonstrates the similari ties and differences. The A term of the van Deemter equation is missing, as expected. The Β and C terms are similar but the inverse gaseous diffusion term has been added. A re-examination of the van Deemter equation has resulted in several new approaches. All agree that the flow term inversely related to gaseous diffusion should be in cluded. This was the consensus of opinion at the Edinburgh meeting. A C term of the form (Ce + Ci)/i
