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 OPTIC 3 Frequently Asked Questions
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| Q: |
How deep must the column go into the injector? |
| A: |
The advised depth is 25 to 26 mm measured from the bottom of the injector bottom nut. More... |
| Q: |
What is the maximum temperature of the OPTIC? |
| A: |
The maximum temperature of the OPTIC 2 and OPTIC 3 is 600°C. |
| Q: |
I want to do a LVI injection but my compounds of interest are very labile. Is this possible? |
| A: |
Yes, ATAS has developed At-Column for these applications. With At-Column a large volume is injected at-once in a liner without packing materials.
After venting the solvent the sample is transferred cool on column |
| Q: |
How do I optimize a cold splitless injection? |
| A: |
To ensure a fast complete transfer install a liner with a small internal volume. This is either a splitless liner (P/No: A100049) or a baffled liner (P/No: A100132).
Use a syringe with a point style 2 or 5 to prevent injecting down to the injector bottom.
Set the injector 20-30°C below the atmospheric boiling point of the solvent.
Set the ramp rate < 8°C/sec, this will prevent explosions and mixing and dilution with the carrier gas.
Set the injector final temperature 25-50°C above the final oven temperature.
The required transfer time is experimentally determined. Transfer times should be long enough to recover the high boiling compounds, and short enough to recover volatiles (< C10) that can be obscured by the solvent peak.
A good starting point is 30 seconds for a splitless liner and 1.5 minutes for a wide bore liner added to the time required to reach the final temperature of the injector.
If high boilers are not recovered the transfer time should be increased in steps of ten seconds, otherwise the transfer time can be reduced to save analysis time.
Set the oven temperature 30-40°C below the atmospheric boiling point of the solvent.
Set the oven initial hold equal or longer to the transfer time.
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| Q: |
Does the OPTIC 3 fits on any GC? |
| A: |
Yes, the OPTIC fits on all common GC types. |
| Q: |
Can the Merlin Microseal be used with the OPTIC 3? |
| A: |
Yes, the Merlin Microseal Septum fits standard on the OPTIC 3.
It's however important to use it with the correct needle gauge, and do not over tight the injector nut. The needle gauge should be 23 and the point of the needle should be a blunt-tip (conical). Please read the Merlin Microseal manual before use. |
| Q: |
I want to do a large volume injection, however, the volatiles are important. Is this possible? |
| A: |
Yes, with the OPTIC you can inject up to 150 µl at-once. Using this technique a recovery of 90% C8 and 100% C9 in hexane is possible. |
| Q: |
I want to do a LVI injection but I have a dirty matrix. Is this possible? |
| A: |
Yes, ATAS GL has developed DMI, difficult matrix introduction for these applications. With DMI the liner and column are protected against in volatile particles, and the used contaminated liners can automatically be replaced. |
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