JCAMP-DX

This format considers so-called labelled data records (LDR) all having the same basic structure of the form descriptor = something , where the descriptor is the name of the LDR and the signifies the end of the label. The lines can be up to 80 characters long, terminating in a carriage return or linefeed. However, LDRs can run over more than one line. 

More details are given in Chapter ly Section 3 of the Handbook. 

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The JCAMP-DX file format is split into the sections CORE and NOTES with the intention of keeping less important data separated from the essential content. The CORE itself contains CORE HEADER and CORE DATA. NOTES are just between HEADER and DATA (see Figure 4-4 for an example). 

Data Analysis. The computerization of spectrometers and the concomitant digitization of spectra have caused an explosive increase in the use of advanced spectmm analysis techniques. Data analysis in infrared spectrometry is a very active research area and software producers are constantly releasing more sophisticated algorithms. Each instmment maker has adopted an independent format for spectmm files, which has created difficulties in transferring data. The Joint Committee on Atomic and Molecular Physical Data has developed a universal format for infrared spectmm files called JCAMP-DX (52). Most instmment makers incorporate in thek software a routine for translating thek spectmm files to JCAMP-DX format. 

With recent rapid increases in the size of computer hard disks and memory, another format, JCAMP.DX (Joint Committee of Atomic Molecular and Physical Data), has become more widespread. It preserves all the numerical values in the original spectrum as well as information regarding the spectrum in an ASCII file. One of the advantages of this format is that it allows all comparison algorithms to be used for further identification of the spectrum (Fig. 10.22). 

TITLE=polystyrene (film 38.lMm) JCAMP-DX=4.24 Nicolet v. 1 DATATYPE=INFRARED SPECTRUM ORIGIN= OWNER=IUT Le Mans DATE=1999/12/16 TIME=13 09 20 DATA PROCESSING=Ratio against background XUNITS=1/CM YUNITS=TRANSMITTANCE... 

Figure 10.22—Example of a JCAMP.DX file read by a word processor. This file corresponds to the spectrum in Fig. 10.1. The header contains information about the spectrum and the data points are organised in sequences of 6 values. Only a few values have been retained.

JCAMP-DX - [INFRARED TECHNOLOGY AND RAMAN SPECTROSCOPY - INFRARED TECHNOLOGY] (Vol 14)... 

Before reaching the point of complete data integration as given above, there are intermediary levels of data integration that are beneficial to better analysis of data from process analyzers. The best case would be to have all the data in a human readable form that is independent of the application data format. Over the years several attempts have been made to have a universal format for spectroscopic data, including JCAMP-DX and extensible markup language (XML). Because many instrument vendors use proprietary databases, and there is not a universal standard, the problem of multiple data formats persists. This has led to an entire business of data integration by third parties who aid in the transfer of data from one source to another, such as between instruments and the plant s distributed control system (DCS). 

JCAMP-DX, a standard format for the exchange of spectra in computer readable form. 

In contrast to typical expert systems, ARC is written in C-h- and includes a rules base in binary format, which can be created with information from different file formats, such as MDL Molfile, Brookhaven Protein Database, Gasteiger Cleartext, JCAMP (DX, JDX, JCM, and CS), binary files (molecule sets, databases, code... 

Neural network methods require a fixed length representation of the data to be processed. Vibrational spectra recorded usually fulfill this requirement. With most applications in vibrational spectroscopy, the spectral range and resolution are fixed, and a comparison of spectra from different sources is directly possible. Appropriate scaling of the spectra allows handling different resolutions to obtain the same number of components in a descriptor. Digitized vibrational spectra typically contain absorbance or transmission values in wave-number format. Most of the spectrometers provide the standardized spectral data format JCAMP-DX developed by the Working Party on Spectroscopic Data Standards from the International Union of Pure and Applied Chemistry (lUPAC) [48]. 

JCAMP-DX is a standardized file format for the representation of spectra, chromatograms, and International Union of Pure and Applied Chemistry (lUPAC). 

Different methods are used to store spectra with less memory space than the original files. The experimental data points are mathematically treated by a deresolution procedure in order to replace them by a smaller number of calculated values (e.g. a point calculated each 4 or 2cm reduces a spectrum to less than 1 Ko). Another standard format is the JCAMP-DX (Joint Committee on Atomic and Molecular Physical Data) for exchange spectra in computer readable form. It preserves all of the numerical values of the original spectrum, as well as all of the related information regarding the spectrum in an ASCII file. Most FTIR spectrometers have JCAMP.DX import/export utilities. This format is compatible with all of the comparison algorithms to enable further identification (Figure 10.20). 

TITLE= CAFFEINE JCAMP-DX= 4.24 DATA TYPE= INFFIARED SPECTRUM ORIGIN= EPA1100.SPC converted Galactic SPC file... 

Figure 10.20 Example of a JCAMP-DX file read hy a word processor. This type of file enables the reproduction of the original spectrum by treatment with a suitable software. Experimental points are arranged in sequences of six data points. Only the beginning and the end of the file have been retained.

To transfer data between different bulk storage media, files of fixed exchange formats are created. The most important exchange format in spectroscopy is that elaborated by the JCAMP/DX format, which was elaborated by the Joint Committee on Atomic and Molecular Data with the following objectives ... 

Table 7.2 demonstrates an example of a JCAMP/DX data file for storing the IR spectrum of epichlorohydrin vapor. Here, the minimum information is given. Further items concern information about the compound, for example, the molecular mass or the... 

Table 7.2 Important information of a JCAMP/DX exchange file for an IR...

Balzers, Bear Instruments, DA5000, EPA I + II, EZ-Scan, GCQ, HP-Chemstation, HP-RTE, ICIS 1 + 2, INCOS, ITDS, ITS40, JCAMP-DX, Mach3, MassLab, MassLynx, MSD, MSS, NetCDF, Saturn, Shimadzu, Shrader, SSX, VG 11-250. 

All spectra were converted to the JCAMP format using the Bruker ATS-JCAMP-DX (4.24) conversion program (Version 1.3). Data transfer to a personal computer was initialized by the Bruker-Kermit program. 

JSpecView is a viewer for spectral data in the JCAMP-DX and AnIML/CML format [75], The program was initially developed at the Department of Chemistiy of the University of the West Indies, Mona, Jamaica, West Indies and is available via sourceforge net under the GNU Lesser General Public License. It is an open-source viewer and converter for multiple spectra (Fig. 7.31). 

McDonald, R.S., Wilks, P.A. JCAMP-DX A Standard Form for Exchange of Infrared Spectra in Computer- adable Form . Appl. Spectrosc. 1988, 42, 151-162. 

The formatting of a database involves the creation of several types of files that are manipulated with specialized software. A source file containing raw analytical data is converted to a library file by reducing noise, eliminating unimportant data and compression. Associated exchange files enable data to be transferred in a standard format such as JCAMP/DX for spectrometric data and JCAMP/CS for chemical structures. 

In most investigations dealing with structure-IR spectrum correlations, digitized spectra containing absorbance values in a wavenumber range from 400 to 4000 cm were used. A standard spectral data format that has gained global acceptance is the JCAMP-DX format. In this ASCII format, the wavenumbers, absorbance values, and other information about the measurement process can be stored. 

JGAMP - Joint Committee on Atomic and Molecular Properties. JCAMP is a format for spectroscopic data and associated structure information, including bridging information such as peak assignments. The JCAMP-DX standard concerns spectral data encoding, JCAMP-CS describes structure information. Both information blocks can be combined. ... 

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