CORCO CHEMICAL CORPORATION
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the "dirty" 10~ 5 torr vacuum. The deposition of carbon in the electron microprobe due to the cracking of organic contaminants of the "dirty vacuum" has been known for only a few years (19, 20, 21). Micro- probes today use Λ-arious means of decontaminating systems (22), e.g. cold fingers, or He, air or argon jets ; but if the vacuum level of the elec- tron microprobe wore in the 10~ 10 torr range, the sample would remain clean for hours. The electron mi- croprobe could be designed with modern vacuum technology to op- erate at least in the 10~ 8 or 10 9 ton· range and make the instrument useful for vacuum technologists studying surface science and also improve the analytical capability and versatility of the instrument. Extrapolations In this review and through se- lected examples we have attempted to show that vacuum technology can improve analytical chemical methods as in mass spectroscopy. Also, several analytical chemical methods exist which have potential applications in vacuum technology if properly adapted. Figure 9 attempts a prediction for the decade ahead. It shows the presently used vacuum levels in various analytical instruments and also an extrapolation for future re- quirements. The future vacuum needs of these measuring techniques differ. Those with potentials for surface studies or higher sensitivi- ties will require better vacuum lev- els. For some methods, better vac- uum levels would not yield much improvement. The most promising and newest analytical methods are connected with X-ray analysis, and electron spectroscopy. These analytical methods, with their great potential are not, or are very rarely, used in vacuum sciences. Electrically charged particles were harnessed long ago by vacuum scientists and put to use for heat- ing, evaporating, pumping, and measuring. Ion gauges were rare 20 years ago; today they can be found everywhere, except on ana- lytical chemical equipment. Re- sidual gas analysers were a novelty 10 years ago; now they are com- monplace. Analytical exploitation of electrons was started a few years ago by vacuum scientists with Auger spectroscopy; today ESCA and EM-SEM techniques are hold- ing much promise for vacuum in- strumentation. X-rays arc specifically interest- ing for vacuum scientists. In the past they were considered a nui- sance and caused much research in connection with ion gauges and l'ga's. X-rays were never used in the vacuum sciences in spite of their great potential. Improvement in analytical chem- ical instrumentation is needed and new vacuum instrumentation is re- quired as well. To this end, inter- action between vacuum science and Figure 9. Extrapolations: 1970-1980 If you need carbon dioxide—free sodium or potassium hydroxide, Corco is the place to go. We can supply, from stock, ClVfree, 50% NaOH and 45% KOH in quarts, gallons or in 5-gallon cubitainers. Our carbon dioxide—free hydroxides meet reagent grade specifications. Corco can also supply you with a complete line of volu- metric solutions, special Kjeldahl NaOH and Karl Fischer solutions. CHEMICAL CORPORATION Manufacturers of Reagent and Electronic Chemicals Tyburn Road & Cedar Lane, Fairless Hills, Pa. 19030 'Phone: (215) 295-5006 Circle No. 26 on Readers' Service Card ANALYTICAL CHEMISTRY, VOL. 42, NO. 11, SEPTEMBER 1970 · 35 A Report NEED CO-FREE NaOH KON PRESENTLY USED FUTURE NEEDS AUGER-LEED INFRARED (ATR) ESCA SCANNING ELECTRON MICR. ELECTRON MICROPROBE X-RAY SPECTROSCOPY THERMAL ANALYSIS MASS SPECTROSCOPY VACUUM UV SPECTROSCOPY 10" Z 10" 4 10 6 10" 8 10~ 10 10' 12 TORR CORCO
Transcript of CORCO CHEMICAL CORPORATION
the "d i r ty" 10~5 torr vacuum. The deposition of carbon in the electron microprobe due to the cracking of organic contaminants of the "dir ty vacuum" has been known for only a few years (19, 20, 21). Micro-probes today use Λ-arious means of decontaminating systems (22), e.g. cold fingers, or He, air or argon jets ; but if the vacuum level of the electron microprobe wore in the 10~10
torr range, the sample would remain clean for hours. The electron microprobe could be designed with modern vacuum technology to operate a t least in the 10~8 or 10 9
ton· range and make the instrument useful for vacuum technologists studying surface science and also improve the analytical capability and versatili ty of the instrument.
Extrapolations In this review and through se
lected examples we have at tempted to show tha t vacuum technology can improve analytical chemical methods as in mass spectroscopy. Also, several analytical chemical methods exist which have potential applications in vacuum technology if properly adapted.
Figure 9 at tempts a prediction for the decade ahead. I t shows the presently used vacuum levels in various analytical instruments and also an extrapolation for future requirements. The future vacuum needs of these measuring techniques differ. Those with potentials for surface studies or higher sensitivi-
ties will require better vacuum levels. For some methods, better vacuum levels would not yield much improvement.
The most promising and newest analytical methods are connected with X- ray analysis, and electron spectroscopy. These analytical methods, with their great potential are not, or are very rarely, used in vacuum sciences.
Electrically charged particles were harnessed long ago by vacuum scientists and put to use for heating, evaporating, pumping, and measuring. Ion gauges were rare 20 years ago; today they can be found everywhere, except on analytical chemical equipment. Residual gas analysers were a novelty 10 years ago; now they are commonplace. Analytical exploitation of electrons was started a few years ago by vacuum scientists with Auger spectroscopy; today ESCA and E M - S E M techniques are holding much promise for vacuum instrumentation.
X-rays arc specifically interesting for vacuum scientists. In the past they were considered a nuisance and caused much research in connection with ion gauges and l'ga's. X-rays were never used in the vacuum sciences in spite of their great potential.
Improvement in analytical chemical instrumentation is needed and new vacuum instrumentation is required as well. To this end, interaction between vacuum science and
Figure 9. Extrapolations: 1970-1980
If you need
carbon dioxide—free sodium or
potassium hydroxide, Corco is
the place to go.
We can supply, from stock,
ClVfree, 50% NaOH and 45%
KOH in quarts, gallons or in
5-gallon cubitainers.
Our carbon dioxide—free
hydroxides meet reagent grade
specifications.
Corco can also supply you
with a complete line of volu
metric solutions, special
Kjeldahl NaOH and Karl Fischer
solutions.
CHEMICAL CORPORATION Manufacturers of
Reagent and Electronic Chemicals
Tyburn Road & Cedar Lane, Fairless Hills, Pa. 19030 'Phone: (215) 295-5006
Circle No. 26 on Readers' Service Card
ANALYTICAL CHEMISTRY, VOL. 42, NO. 11, SEPTEMBER 1970 · 35 A
Report
NEED CO-FREE NaOH KON
PRESENTLY USED FUTURE NEEDS
AUGER-LEED
INFRARED (ATR)
ESCA
SCANNING ELECTRON MICR.
ELECTRON MICROPROBE
X-RAY SPECTROSCOPY
THERMAL ANALYSIS
MASS SPECTROSCOPY
VACUUM UV SPECTROSCOPY
10"Z 10"4 1 0 6 10"8 10~10 10 ' 1 2
TORR
CORCO
