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Category: MSD ChemStation / RTL (Retention Time Locking)

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MSD ChemStation / RTL (Retention Time Locking)

1. My lab performs high volume analysis of relatively routine, yet complex samples. Often we experience retention drift that requires us to manually re-calibrate and process our data. Is there a way to adjust the retention times automatically? (id=17)

Revision B.01.00 or later GC/MS MSD ChemStations (G1701BA/G1710BA) include a feature that automatically monitors and updates retention time drift associated with routine column and pressure related drift. This feature requires a 5973MSD/ 6890GC (with electronic pressure control)and autosampler (ALS). “Closed Loop” Retention Time Locking is a feature in “Enhance” mode of data analysis. Check out GC/MS MSD ChemStations On-line Help, or for a more specific question, Ask Dr. ChemUser.

2. I have heard that the GC/MS MSD ChemStation has the ability to lock retention times and automatically update calibration retention times. What do I need to implement this functionality? (id=18)

?Closed Loop? Retention Time Locking (RTL) is a standard feature of the GC/MS MSD ChemStations (G1701CA/G1710CA) revision C.00.00 or later. It is implemented in the ?Enhanced? mode of data analysis.

3. I am currently Screening for pesticides using GC and GC/MS and heard there was a pesticide library for use with Retention Time Locking. How can I get access to this database? (id=19)

The G1049A RTL Pesticide Screening library contains 567 environmental pesticides/ chemicals and is sold separately. It requires GC/MS MSD ChemStations (G1701BA) revision B.01.00 or later. It also requires Electronic Pressure Control (EPC) for the Agilent GC.

4. I would like to use RTL (retention time locking) on just GC data. Is this possible? (id=20)

Yes. The G1701BA (B.01.00) GC/MS MSD ChemStations software supports RTL and instrument control and data acquisition for the 6890GC. No MSD is required. Infact, the software will conrtol up to 4 GCs. Need more details? Ask Dr. ChemUser.

5. How do I create my own “custom” Retention Time Locked screening library? (id=21)

There are three 3 basic steps for creating your own RTL screening library. The process requires appropriate experience with Library search and “Enhanced” mode of Data Analysis (G1701BA, B.01.00). The three steps are:

1)Create a GC/MS method that is RT Locked.
2)Create a MS library from samples analyzed with the RT Locked method.
3)Converting the library to a screening database.

6. What are the advantages of Retention Time Locking? (id=22)

RTL is best used when:

1. moving a method to a different instrument system (like hardware components)
2. validating the system performance and for later comparison
3. after column maintenance (changed or trimmed)
4. general troubleshooting (pressure leaks)
5. to compensate to different detector outlet pressures

7. How does Retention Time Locking (RTL) screening software work? (id=23)

When used with the G1049A RTL Pesticide library, the GC/MS data is acquired using a method provided with the library (RTLPEST.M). The software then uses a narrow RT window to compare ions near the expected elution times in the library to those in the acquired data file. Retention times and ion abundance are used to determine possible hits. The result review functionality is based on the “Enhanced” mode Qedit feature and simplifies the interactive review/ confirmation process.

8. Are there any instrument configuration limitations when using Retention Time Locking (RTL)?K (id=24)

Yes. The RTL functionality is supported only on 5973A/N MSDs and 6890GCs with Electronic Pressure Control (EPC).