CHICAGO APPARATUS COMPANY
1
Fast, \ MOLECULAR Accurate W WE | G HT /DETERMINATIONS f w το so,ooo ' 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. lOtl LINDA VISTA AVINUt MOUNTAIN VIEW 1, CALIFORNIA Circle H*. 121 el Kilters' Strtict Cut PUT HIGH FREQUENCE SOUND TO WORK IN YOUR ΙΛΒ 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 magno- restrictive design operating in the 20 KC 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 up 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. MODEL SG-2 PRICE *495°° 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. CHICAGO APPARATUS COMPANY 1735 North Ashland Avenue, Chicago 22, Illinois KANSAS e m r — I B ! « Μ · » SU K m OU t. Mbsesri · ST.lOUIS-SmBrowAr^Stleefcl^Mtawrl Circle No. 118 on Readers' Service Card REPORT reason and caused much the same revolution. The acclaim would have been great as it has been for other accidental discoveries. But 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 that 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. In other words, a term covering the effect of gaseous diffusion perpendicular to the column axis which works to coun- teract the fact that 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 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 (C e + Ci)/i 2 6 A • ANALYTICAL CHEMISTRY , /„ D„ . 1 + 6fe + life' »„r„» , du = ^ 2 - + 24 ( 1 + fe ), S7 + e(i k +ky V ^) dx ' (2)
Transcript of CHICAGO APPARATUS COMPANY
Fast, \ MOLECULAR Accurate W W E | G H T
/DETERMINATIONS f w το so,ooo ' 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 L I N D A V I S T A A V I N U t M O U N T A I N V I E W 1 , C A L I F O R N I A
Circle H*. 121 el Kilters' Strtict Cut
PUT HIGH FREQUENCE SOUND
TO WORK IN YOUR ΙΛΒ
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 magno-restrictive design operating in the 20 KC 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 solutions is minimized and it works efficiently up to 400° F. when required.
Our customers are regularly reporting new and useful applications for the SG-2. From knowledge of these special applications, we can help you with your problems.
Write us—our facilities are at your disposal.
MODEL SG-2 PRICE
*495°°
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.
C H I C A G O A P P A R A T U S C O M P A N Y 1735 North Ashland Avenue, Chicago 22, Illinois
KANSAS e m r — I B ! «Μ·» SU K m OU t. Mbsesri · ST. lOUIS-SmBrowAr^St leefc l^Mtawrl Circle No. 118 on Readers' Service Card
REPORT
reason and caused much the same revolution. The acclaim would have been great as it has been for other accidental discoveries. But to have set out with the aim of proving previously conceived theoretical ideas of the advantages possible required a genius and an insight characteristic of real scientific creativity.
Fortunately Golay was not content 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 that 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. In other words, a term covering the effect of gaseous diffusion perpendicular to the column axis which works to counteract the fact that 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 chromatography.
A comparison of Dr. Golay's Equation 2 for efficiency of open
tubular columns with the van Deemter Equation 1 for packed columns demonstrates the similarities 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 included. This was the consensus of opinion at the Edinburgh meeting. A C term of the form (Ce + Ci)/i
2 6 A • ANALYTICAL CHEMISTRY
, / „ D„ . 1 + 6fe + life' »„r„» , du = ^ 2 - + 24 ( 1 + fe), S7 +
e(ik+kyV^)dx' ( 2 )
