📊 GCMS Data Analysis
Post-Run Chromatogram & Spectral Processing
Step-by-step procedure for analyzing GCMS data, scaling chromatograms, conducting NIST library searches, and extracting reports.
◈ 1. Loading & Chromatogram Prep
Data Retrieval & Scaling
- Open the GCMS Data Analysis software.
- Navigate to Load Data File → Change Path. Select the folder corresponding to the current analysis month and load the specific raw data file.
- Go to Chromatogram → Chromatogram Scaling...
- Click OK iteratively and choose Cont. to scale. Adjust the view continuously until discrete, distinct peaks are visible (adjusting until "nampak peak").
◈ 2. Automated Integration
RTE Integrator & Library Search
- Select Chromatogram → Select Integrator...
- Choose the RTE Integrator from the dropdown/list, then click Integrate.
- To generate initial matches, navigate to Spectrum → Library Search Report.
- When prompted for output, select Screen and click OK to view the preliminary results before printing.
◈ 3. NIST MS Search (Manual Verification)
Manual Peak Integration
- If specific peaks require deeper manual investigation, initiate the NIST MS Search workflow.
- Zoom extensively into the specific target peak on the chromatogram canvas.
- Perform a Right Click explicitly inside the peak apex, and another Right Click outside the peak (on the baseline) to capture the background spectra.
- Navigate to Spectrum → Subtract to cleanly deduct the background noise.
- Double Right Click on the newly subtracted sub-graph element at the bottom of the window to instantly execute a direct cross-reference against the complete NIST Spectral Library.
🔍 Threshold: Positive Confirmation
Review the NIST Match Quality Score. A match quality of 80% or greater is required to definitively consider the spectral matching as POSITIVE.
◈ 4. Printing & Documentation
Reporting Logistics
- To print specific analysis windows: Go to Print Spectrum → Selected Windows, and input the relevant Windows Number #.
- Load the next sequential data file, integrate it, and then explicitly Print "Depan Belakang" (Double-sided printing to save paper/file correctly in records) when dealing with consecutive sequence injections.
- Print the comprehensive Library Search Report explicitly for Injection No 1. (Refer back to GCMS Operation rule: 2 injections per bottle).
- Logbook Documentation: Photocopy the relevant pages from the GCMS Logbook. Manually highlight the corresponding Sample Number on the photocopy.
- Attach the highlighted logbook photocopy securely along with the printed chromatogram maps and spectral scan reports to form the complete analysis docket.
Previous Step
GCMS 8890 Operation Guide
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