Figure 2.TRS-80 screen display of reciprocal rate versus fractional conversion. Students select residence times by moving the cross along the horizontal axis.
comuutation and drawing incite the user to trv m a w solutions witha growing n u m h r ol;reactors in order to improbe his skill. So when "ulavine" with the cornouter, the future enrineer will fmd very easily &at, for a given operation, an optimal solution exists because of the evolution of the volume with the number of reactors. Such an optimization would not be so carefully done by traditional means. This program is written in BASIC for aTRS80 Model I1and needs 9 Khytes of RAM. Documentation including a listing (with sample executions according to the several options) ran he obtained, free of charge, by writing to Ozil.
Employing Data Management Software for the Production and Searchina of Customized Mass Spectral ~ibraries Edward M. Gouge
Presbyterian College Clinton. SC 29325 Although a number of computerized mass spectral data hases are currently available (I),such factors as accessibility, size, specificity, andlor cost of the hases may make them inconvenient for use, particularly in institutions devoted mainly to teaching and less to research. T o overcome this problem a user may choose to create his own machine-based library for use with a microcomputer. This can he accomplished by writing a program that will, besides entering the spectral data, incoroorate a search alsorithm to scan the data for the ourowe of loc'ating a match to ;he spectrum of a n unknown cokp&nd (.2.) .Another uossihle anuroach to the creation of a soectral data hase is to employ commercially available data management (information management or electronic filing) software. A
-
As an aodication of the latter techniaue. we wish to describe .. the construction of a file of mass sl,c!&i4 data and a means of searchinr that file usinr PFS:FILE software. (PFS:FII.E , is a produ>t of software Publishing ~ o r ~ o r & i o n1901 Landings Drive. Mountain View. CA 94043.) This uarticular software, one i f several comm&cially available k~ectronic filing systems, has been developed for use with the Apple, IBM, COMPAQ, and Texas Instruments microcomputers. Data storage is accomplished by first designing a file form in which the data is to he inserted. Figure 3a shows the tailored form for each compound in our lihrarv. Information to the left of a colon in the f h m is designnted ks an item and is simply a descriptor awaiting information that will he inserted to the right ofthe colon. o he information indicated in the first two lines is self-explanatory., the last line is designed for the listing, in descending order, of the compound's five mle values of ereatest relative intensitv. this method of listine . (Althoueh . mass spectral data is particularly popular for small libraries containine comoounds with molecular weiehts less than 200. other teckiques (3) could be used.) A c o m 6 e t d form for one of the cumoounds in the lihrarv is shown in Fieure 3b and represents iata, taken with permission, from ref. (2). Although a t present our library is much smaller, simple calculations suggest that over 500 compounds could be catalogued on a single 5V-in.. single-sided. double-densitv, soft-sectored m i ~ i d i s k ~ m p 1 o the y i ~descrihed filing form. Using simple and easily executed commands, PFS:FILE allows such functions as form design, addition to and deletion from the file, and form redesign without loss of inserted information. The simplicity of spectral file construction and editing is matched by the ease of searching the file. Using information obtained from the mass spectrum of an unknown compound, a blank file form is filled withdata t o whatever extent is possible. These data would most typically be a combination of mle values of several of the more intense peaks and the molecular ion peak (inserted as the MW item), M+, although inserting the symbols, > or
