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to Chemistry, UWI-Mona, Home PageThe first program, FTtoPC, allows connection, via RS-232, from a Perkin Elmer 1605 FT
IR to a PC and captures the intensity information in the standard JCAMP-DX version 4.24 DIFDUP compression format.
FTtoPC is a DOS based programme written in Borland's Turbo Pascal 5. You will need
to configure the communication parameters on the FTIR using the setup softkeys and be sure
to send the data across in JCAMP-DX format. You can use either COM1 or COM2 with this version which was last updated 3rd Dec, 1995 (9264 bytes).
Originally this ran on an old XT at 9600 baud. More recently we have been using a 486 DX
and noticed that some lines had dropped data. I have now lowered the BAUD rate to 2400,
where it seems to work without data loss. (There was no setting for 4800 on the FTIR).
We have recently purchased another HP 5890 GC and the latest version comes with a
Headspace analyser and PC Datastation. The output from the GC can be sent to file using
the TABULATE command,
(e.g. TABULATE X1:X2,filename,X
where X1:X2 is the range - default is all
filename is where output is sent
X is the register containing your data)
This produces columns of numbers, such as:
time counts time counts time counts time counts 0.000 49559 0.003 49565 0.007 49565 0.010 49566 0.013 49558 0.017 49562 0.020 49571 0.023 49573 0.027 49563 0.030 49574 0.033 49563 0.037 49565 0.040 49563 0.043 49567 0.047 49565 0.050 49571
where the numbers are incremented across the page, then down.
I have written a simple conversion program (size = 44765 bytes,
last modified 17th July, 1997) that can be used to generate JCAMP-DX files from these
files.
Be advised that the TABULATE command introduces rounding errors such that the X values are
NOT evenly spaced (deltaX varies). To correct for this it is possible to import the file
into a spreadsheet then use the FILL/SERIES command to generate new columns of X values
and then resave the file.
A number of HP 5890/6890 GCs with MS detector are in Jamaica and the Department of
Chemistry has recently purchased their own.
Looking at the software that was shipped with the 5973 Mass Selective Detector, dated
October 1996, I realised that the syntax for the TABULATE command is different to that for
the GC above (it requires double quotes around the file names) and the output is sorted
differently as well, for example:
m/z abund. m/z abund. m/z abund. m/z abund.
50.10 874 61.10 753 75.05 817 88.05 777
51.10 1751 63.05 721 77.05 3386 89.05 580
52.10 881 65.05 1475 78.05 864 91.05 2520
53.10 2625 66.05 1098 79.05 5174 93.05 1090
Note that the data is now arranged from top to bottom and not left to right.
Since Mass Spectra can be characterised reasonably well from the 20 most intense peaks, I
have written a small utility (size= 46411 bytes) to convert the
output file from the TABULATE command to a JCAMP-DX file containing only the top 20 peaks.
The program was last modified, 17th July, 1997.
Our HP ChemStation software (version G1701AA A.00.00) has an import and export for
JCAMP-DX files under the library settings menu. The data files created from this however
are labelled as JCAMP-DX version 4.10 and do NOT comply with version 4.24 or the more
recently published version 5.0 specifications.
They cannot be viewed with our viewer unless you edit the files and add/correct the following header items. While some of this appears cosmetic, without it our program can NOT display your information
##TITLE=Library Entry 1 $$OK
##JCAMPDX=Revision 4.10 $$ remove the word revision, change to 5.0
##DATA TYPE=MASS SPECTRUM $$OK
$$add ##DATA CLASS= PEAK TABLE
##SAMPLE DESCRIPTION=QI=82 Derivatives; Metals; Misc. Natural products; Fatty acids and Lipids;
##NAMES= NIST 1992 $$OK
##CAS NAME=Methane $$OK
##MOLFORM=CH4 $$ C H 4
##CAS REGISTRY NO=000074-82-8 $$OK
##MP= -300 $$OK
##BP= -300 $$OK
##MW= 16.031 $$OK
##$RETENTION INDEX=0 $$user defined
##$CONDENSED SPECTRUM=NO $$user defined
##NPOINTS= 7 $$OK
$$the following compulsory items are missing:
$$ ##ORIGIN, ##OWNER, ##XUNITS, ##YUNITS, ##XFACTOR, ##YFACTOR
$$ ##FIRSTX, ##LASTX, ##FIRSTY
##XYDATA=(XY..XY) $$ this should be ##PEAK TABLE= (XY..XY)
2 117 $$ ##XYDATA is ONLY used for continuous fixed increment data types
12 380
13 1069
14 2042
15 8879
16 9999
17 164
$$ add ##END=
A simple web form can be used to generate a JCAMP-DX file "on the fly". You provide the intensities for up to 15 peaks in increasing mass order. This uses a combination of JavaScript and CGI so can only be run with a Java enhanced browser. The scratch file produced is displayed in a new browser page, if you have installed our plugin. Let me know if you find it useful!
Note that I am making these programmes freely available and will not be held accountable for misuse......
Standard Disclaimer applies etc.
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