Instrumentation Donald A. Burns Technicon Industrial Systems 511 Benedict Avenue Tarrytown, NY 10591
Downloaded by UNIV OF CAMBRIDGE on September 10, 2015 | http://pubs.acs.org Publication Date: October 1, 1981 | doi: 10.1021/ac00235a810
Automated Sample Preparation Scene I: Analytical laboratory, mid-morning: Carl Chemist (scowling): "Blast! This analysis can be done in five minutes, but it takes 20 minutes to get each sample ready. I'll be here all night!" Anabelle Analyst (equally dejected): "You think that's bad? The cleanup procedure for these samples requires nine different steps and a ton of glassware to wash. There must be a better way!" Scene II: Same laboratory, several weeks later:
This brief dialogue addresses two important problems facing the analytical chemist: the labor-intensive aspect of sample cleanup prior to analysis and the inefficiency that results when sample preparation and sample analysis operate in different time frames. These two analysts, and most of their colleagues, surely have sufficient reason to squawk when they discover that many so-called fully automated methods have all but ignored the major effort required for manual sample treatment prior to sample introduction into the system. Analysts want access to an instrument that will accept unmeasured, untreated samples at one end and provide a full report, in correct concentration units, at the other end, requiring no operator involvement beyond keeping the reagent bottles full. Such instruments (see Figure la) do exist and have been described for gas chromatography (GC) (1), and more recently for high performance liquid chromatography (HPLC) (2). Inside these analyzers several types of operations may be performed, some examples of which are shown in Figure lb. But not all instruments are fully automated, nor should they be. It is often advisable to stop part way through the procedure and insert an additional step: temporary storage. Figure lc illustrates such a pause: a 0003-2700/81/A351-1403S01.00/0 © 1981 American Chemical Society
Carl (smiling): "Say, this off-line sample prep unit is great! The instrument processed 40 samples overnight, unattended, and the analyzer can now handle them at 12 per hour. They'll all be finished by noon!" Anabelle (equally ecstatic): "You think that's good? Take a look at this machine: It's doing the entire sample cleanup by itself, with no dirty glassware, and the RSDs are lower than I used to get. Thank goodness for automation!"
Figure 1 . A n a n a l y t i c a l i n s t r u m e n t : (a) t h e a n a l y s t ' s d r e a m ; (b) t y p i c a l o p e r a t i o n s ; (c) t w o m a j o r divisions (a) Sample-».
Analyzer
(b) Analyzer 1. 2. 3. 4. 5. 6. 7. 8.
Sample Definition Sample Reduction Physical Cleanup Chemical Modification Separation Chemical Modification Detection Data Manipulation
y
Q S
(20) Allington, R. W.; Hansen, M. D. Am. Lab. 1977,9 (9), 47. (21) Du Pont Co., Wilmington, Del.; Prep I. (22) For example: Sep-Pak (Waters Asso ciates, Milford, Mass.); Extube (Analytichem International, Lawndale, Calif.). (23) Lantz, R. K.; Eisenberg, R. B. Clin. Chem. 1978,24 (5), 821. (24) Technicon Industrial Systems, Tarrytown, N.Y.: ASP. (25) Riviera, G. M. In "Advances in Auto mated Analysis"; Mediad: Tarrytown, N.Y., 1976; Vol. 2, pp 347-9. (26) Technicon Industrial Systems, Tarrytown, N.Y.: SOLIDprep-II. (27) For example, Hanson Research Corp., Northridge, Calif.: Dissograph. (28) Technicon Industrial Systems, Tarrytown, ISTY.: SASDRA. (29) Bellar, Τ. Α.; Lichtenberg, J. J. Re port No. EPA-670/4-74-009 (NERC, ORD); Cincinnati, Ohio, 1974. (30) For example: Chemical Data Systems, Oxford, Pa.; Hewlett-Packard, Avondale, Pa.; NuTech Corp., Durham, N.C.; Spex Industries, Metuchen, N.J.; Tekmar Co., Cincinnati, Ohio. (31) Tekmar Co., Cincinnati, Ohio; Auto matic Sampler Model ALS. (32) Hofman, L. F.; Bouley, A. M.; Barron, E. J. Clin. Chem. 1977, 23 (9), 1628. (33) Hormann, W. D.; Formica, G ; Ramsteiner, K.: Eberle, D. O. J. Assoc. Off. Anal. Chem. 1972,55, 1031. (34) Marsh, J. A. P.; Kibble-White, R.; Stent, C. J. Analyst (London) 1979,136. (35) Ramstad, T.; Mahle, N. H.; Matalon, R. Anal. Chem. 1977,49, 386. (36) Siggia, S. In "Instrumental Methods of Organic Functional Group Analysis"; Wiley: New York, 1972; ρ 22. (37) Coulson, D. M. J. Assoc. Off. Anal. Chem. 1975,58,174. (38) Bartels, H.; Werder, R. D.; Schurmann, W.; Arndt, R. W. J. Automatic Chem. 1978, ; (1), 28. (39) Burns, D. A. Res./Dev. 1977, ρ 22. (40) Ionics Inc., Watertown, Mass.; DigiChem 4000 programmable chemical analysis system. (41) Waters Associates Inc., Milford, Mass.: Model 150C liquid/gel permeation chromatograph. (42) Technicon Industrial Systems, Tarrytown, N.Y.: FAST-LC. (43) Dolan, J. W.; van der Wal, S.; Ban nister, S. J.; Snyder, L. R. Clin. Chem. 1980,26 (7), 871.
F i A t r o n S y s t e m s , Inc. 6651 N. Sidney Place (414) 351-6650 Milwaukee, Wl 53209
Donald Burns received his AB in chemistry from Syracuse University, his MS in organic chemistry from the University of Puget Sound in Tacoma, Wash., and his PhD in biochem istry from Purdue University. He is currently director of R&D for Techni con Industrial Systems where his re search involves automation and com puterization of analytical instru ments.
SOLUTIONHANDLINGS Y S T E M S CIRCLE 59 ON READER SERVICE CARD 1418 A • ANALYTICAL CHEMISTRY, VOL. 53, NO. 12, OCTOBER 1981
