3M ANALYTICAL SYSTEMS BULLETIN #2
MiniBeam Ion Gun Offers New Precision, Lower Cost You'll find that the 3M MiniBeam Ion Gun system delivers more accurate analysis data . . . with greater control . . . than ever before possible. Yet it will actually cost you less than other, less capable ion sources. The easy-to-use system produces a scannable ion beam with a variable diameter you can adjust to less than 125 microns for pinpoint accuracy. And it features current densities over 700 μ A/cm 2 , beam energies up to 5 keV. and spatial resolution of less than 100 μ m.
Sample current and elemental imaging This wide area sample current image of an electronic circuit illustrates how you can use the MiniBeam with low voltage to locate sample areas quickly and easily. An increase in voltage gives you more precise viewing of smaller areas. W h e n you c o m bine the MiniBeam wit h a s u r f a c e analysis technique ( s u c h as 3 M S I M S ) you'll get clear, accurate elemental images such as t h i s Na c o n t a m i n a t e d Si w a f e r ( s h o w n h e r e in c o l o r t o d r a m a t i z e the image). You'll discover a whole new form of precision with this breakthrough approach to top monolayer analysis of all types of samples.
Compatibility proven by extensive current use with existing equipment For years, the MiniBeam was confined to use in 3 M Surface Analysis systems. However, for some time
Analytical Systems/3M Building 53-3S 3M Center Saint Paul, Minnesota 55101 612/778-4009
now it has been performing on a variety of systems in a great many firms. It's compatible with A E S , ESCA, I S S , S E M or S I M S techniques. You'll find you can use this compact, modular MiniBeam Ion Gun as a surprisingly inexpensive addition to your existing analysis equipment. And . . . you'll find it attaches quickly and easily.
Free Information kit reveals all the facts You'll learn m o r e a b o u t the MiniBeam — and how it can give you more com plete surface d a t a than your present equipment may offer — by sending for this free i n f o r m a t i o n kit entitled "New Dimensions in Surface Analysis." Get the facts a b o u t this effec tive approach to problem solving from the surface analysis specialists. Simplv call 612/778-4009. or write to the address below.
In Europe Cambridge Instrument C o m p a n y GMBH D4600 Dortmund 1 Postfach 1404 West Germany (0231) 126086-89 CIRCLE 139 ON READER SERVICE CARD
1130 A · ANALYTICAL CHEMISTRY, VOL. 5 1 , NO. 11, SEPTEMBER 1979
3M
Raw Material
i s o l a
Solvent Partition
Ion Exchange HPLC
0.1% Collection Impurity
Reverse Phase HPLC
•KSH
Why there's no better acid than a Corco acid.
•ΕΠΙΖΕβ
•ΕΠΙΖΕβ
iùiZL: Isolated Impurity
Not 6-N-phenyladenine
in
I D E N T I F I C
GC/MS
Synthesis
E
O-pHENYLADENINE
Figure 7. Flow diagram of problem solving
ed adenine derivative and suggest sub stitution a t the N-9 position. In an effort to confirm t h e hypothe sized structure, 9-phenyladenine was synthesized. Its mass and IR spectra were obtained and compared with spectra of the adenine impurity. T h e infrared spectrum of the synthesized A/-(9-phenyl)adenine is shown in Fig ure 6. T h e fingerprint region of this spectrum is identical to that of the isolated impurity. T h e mass spectrum of the synthesized compound was the same as t h a t obtained from the raw material contaminant. Once the impu rity was identified, changes were made in t h e production process to ensure t h a t 9-phenyladenine would not be present in the raw material. Identifi cation of the impurity and elimination of it as a contaminant in the raw ma terial enabled production of adeninefortified blood storage solution to con tinue. T h e general scheme and approach to solving this particular problem is shown in the flow diagram in Figure 7. T h e most significant factor is that assumptions were made about the properties of the impurity based on its chromatographic behavior. This in formation was then used to make an
educated guess about how best to iso late t h e impurity. Furthermore, the data obtained from several different instrumental techniques were com bined, and a hypothesized structure of the impurity was fomulated based on the assembled data. T h e hypothe sized structure was then confirmed by synthesis. Acknowledgment
We would like to acknowledge L. Streips for analytical work, and A. Berger and S. Scharffenberg for syn thetic work.
References
(1) G. B. Bartlett, "Changes of red cell phosphate compounds during storage of human blood in ACD," International Symposium on Erythrocytes, Thrombo cytes, Leukocytes, Vienna, 1972, pp 139-148. (2) C. W. Gehrke and D. B. Kaking, J. Chromatogr., 61, 45^63 (1971). (3) J. A. McCloskey, Mass Spectrometry in Nucleic Acid Chemistry, in "Basic Principles in Nucleic Acid Chemistry," P. Tso, Ed., Academic Press, New York, 1974, pp 209-309. (4) Sadtler Research Labs, "Infra-red Spectra, 1969," Spectrum No. 1559.
All Corco acids are certified reagent grade acids. We've been specialists in reagent grade acids since 1953. And we've built our reputation on meeting the requirements and specifications of our customers, ACS and ASTM. Corco can provide reagent grade hydrochloric, nitric, sulfuric acids and sodium hydroxide—plus acetic, fuming nitric, fuming sulfuric, hydrofluoric, perchloric and phosphoric acids. Also bases, solvents and specialty chemicals. When you require the highest purity, you can rely on Corco to deliver. From pints to tank trucks. Write, call or circle the number for more information.
CORCO CORCO CHEMICAL CORPORATION Manufacturers of Reagent & Electronic Chemicals Tyburn Road & Cedar Lane · Fairless Hills, Pa. 19030
(215) 295-5006 CIRCLE 35 ON READER SERVICE CARD
ANALYTICAL CHEMISTRY, VOL. 5 1 , NO. 1 1 , SEPTEMBER
1979 ·
1131 A
