Application Note #6

Agilent Technologies ChemStation Macro Programming

Description of Technique:

The DOS ChemStation is Agilent Technologies Windows-based data acquisition and control software for instrumentation. The ChemStation includes a full-featured macro programming language that can be used to create custom user applications. The macro language is so complete that many of the standard ChemStation operations are actually performed by macro programs. Consequently, the ChemStation can be easily extended to provide custom data acquisition, control, analysis, and reporting functionality.

Example Applications:

Improve Efficiency

Automate tasks that you must frequently perform manually

Provide organized Information from Raw Data

Custom reports for process control, quality assurance, or regulatory compliance
Industry-specific data reduction and analysis

Create New Capabilities for the ChemStation

Custom data acquisition and control systems
Custom performance evaluation or system suitability tests

Specific Example:

Automated Mass Spectral Data Reduction & Analysis for Petroleum Refining

A challenge associated with the analysis of petroleum refining samples by GC-MS is to extract useful information from large data sets generated in typical analyses. Even someone skilled in the interpretation and evaluation of mass spectral data is challenged to evaluate thoroughly all the data that is present in these complex samples. Manual data evaluation and library searching can also be very time consuming. A practical way to solve this problem is to reduce data to information by automating the identification, evaluation of quality, categorizing, sorting, and reporting steps using a macro program. Once the data is presented to the user as organized information, it becomes available for decision making. Manual data evaluation techniques can then be targeted to specific areas of interest extracted from the original data set.

Partial List of Macro Features:

Automatically integrates the TIC, and library searches every peak that is detected
Evaluates the quality of the library search result and sorts each match into "clean", "tentative", and "unknown" categories
Determines the class (CH, CHO, CHS, CHN, Other) for each of the clean and tentatively identified peaks using the molecular formula from the library search
Determines the degree of unsaturation (the value of "x" in CnH2n+x) for each of the clean and tentatively identified peaks using the molecular formula from the library search
Sorts the clean and tentatively identified compounds by class, degree of unsaturation, and retention time
Allows three different reports to be generated with increasing detail and complexity

Sample Report Output: One-page summary report

Condensed Summary Class Report
======================================================================================================
File:				C:\HPCHEM\1\DATA\SAMPDATA.D
Operator:			SJH
Sample Name:			Test Sample
Method:				STANDARD.M
Unknown Spectrum:		Peak average
Integration Params:		Autointegrate
"Clean" Match Quality:		70
"Tentative" Match Quality:	40

Total Ion Chromatogram

 

======================================================================================================
CLASS		CLEAN RESULTS		TENTATIVE RESULTS		CLASS TOTALS
======================================================================================================
CH:		46 Pks; 22.2 Area%	65 Pks; 28.7 Area%		111 Pks; 50.9 Area%
CHO:		 2 Pks;  0.7 Area%	27 Pks; 11.5 Area%		 29 Pks; 12.2 Area%
CHS:		 0 Pks;  0.0 Area%	 0 Pks;  0.0 Area%		  0 Pks;  0.0 Area%
CHN:		 0 Pks;  0.0 Area%	 2 Pks;  0.8 Area%		  2 Pks;  0.8 Area%
Other:		 2 Pks;  0.6 Area%	19 Pks;  8.6 Area%		 21 Pks;  9.2 Area%
Unknown:								 54 Pks; 26.5 Area%
======================================================================================================
Total Identified:	164 Peaks and 73.51 Area%
Total Unknown:		 54 Peaks and 26.49 Area%

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