Відео

Yes, D7169 works exactly the same way, except an additional step of calculating total theoretical area so when converting accumulated area to weight percentage, you gotta divide it to total theoretical area.

@@LearningbyDoingwithPeterTran Thank you so much!!😊

Hello, the only drawback I have ever encountered was the Fid baseline was upset for a few seconds when activating the gas saver mode from more than 500 mL/mjn down to 20.

Hello, LOQ is typically calculated as Blank + 10SD. Statically speaking, if you calculate SD from 8 runs just like LOD, 10 SD is equivalent to 99.999% probability that the signal is not noise. In short, with 8 runs, 3 SD (or LOD) is 99% while 10 SD (LOQ) is 99.99%.

Hello, there are many vendors providing the suitable column for both He and N2. Restek is one of those.

Thanks, glad you found it helpful.

Hello, unfortunately oxygenates do not follow the relative response factors as of the normal hydrocarbons. You will need to determine their response factors experimentally.

Hello, would you mind sharing more ?

@@LearningbyDoingwithPeterTran Maybe you explained it in your other videos, I didn't watch them, but what you calculated is if second value is in repeatability range. Your math to check if value is in proper % range is good, but methodology is not. One cannot calculate repeatability using only 2 values. Assuming that your instrument has random distribution you have to have more average values from run, then calculate relative standard deviation (RSD) and if the RSD is in the range you can say that the process is repeatable or not.

You are welcome

That would be too general to talk about. However using timed peak width and slope sensitivity would be more than enough for most if not all chromatograms.

Hi, no it does not apply to TCD

You are welcome.

Hello, D2887 reports weight% while D86 reports volume%. Unless you are converting weight% to volume%, I don’t see any points of comparison.

You are welcome. Make sure to check out other parts to get a full understanding of this method.

You are welcome !

물론이죠

Hello, it seems like you are referring to the threshold in MSD Chemstation’s integration. If so, there is no formula to correlate its value to concentration as far as I know. You would probably want to run your 0.5 ppb first then slowly adjust the threshold until your target peaks start integrated.

Thank you Sir!

You are welcome. Hope the video points you to the right direction.

Update: I was able to update the initialization sequence file name to an existing file in the chemstation.ini file. I'm working with v2. something... I would never have figured this out on my own. Thank you again! Now if only I could fix the pump on my prep HPLC so the flow doesn't randomly cut out me.

Great to hear that. Cheers.

Thanks for viewing, have a good day

Hello, that’s normal. When you start the data acquisition, the GC will clear the gas saver mode automatically to get it ready for injection (by default). Alternatively you can always press the prep run button before your analysis.

You have to press configuration button on GC keypad and select instrument option there, you will find autoprep run On and off you can choose as per your need

From where gas saver flow come and In which part it is flowing , is it coming from inlet side or where? Please answer urgently

It’s coming from your external gas supply of course. The flow rate is controlled by the EPC. When gas saver mode is active, the saver flow is the split flow. Please refer to Part 1 for more details.

Hello, the option is visible by default as long as the version you are using is C.01.09 or later. I’m pretty sure C.01.07 and earlier do not have the custom code option but not quite sure if it would be available in C.01.08

Glad you find it useful. Feel free to drop any questions you might have here.

Glad you solved the problem

I'm not very familiar with LC configuration so I guess you would need to reconfigure the modules

Hi, the easiest option would be to configure a new instrument and copy the data, methods, sequences, templates over. If that still does not work high chance the software has corrupted that you might need to reinstall it.

Did you mean the software you are using is MSD Chemstation ? If so you would have to configure the library to the software in order to show the chemical structure of the hint during MS search. Let me know if it’s the case then I can walk you through the process.

@@LearningbyDoingwithPeterTran Hello, I am writing to you from Colombia. what you say is correct. When I want to review a peak, the usual information appears, only the chemical structure no longer appears. If you can guide me, I would appreciate it. I searched the web but didn't find any help. I remind you that my MSD-GC (5975-6850) works with Chemstation and that software is already old. this is what i tell you. minute 5:30. the information appears minus the structure. ua-cam.com/video/Wef1yjrjU1Y/v-deo.html Thank you

Have you linked the NIST library (disc 2) to the software ? You could possibly switch to the Demo.L first and load a demo data which should show the chemical structure to ensure the software is working properly.

Yes both mean and SD are available in the statistical report for your LOD calculation. For the message you are getting it’s probably your sample type defined in the sequence does not match sequence output number 8 as it is strictly for “sample” type only. You may want to try output 7 or 9 (I can’t remember) but it’s said for calibration type. Alternatively reprocess your sequence to change all data to “sample”. If you happen to use Openlab Chemstation head over to my other video in the limit of detection series in which i am showing how to generate a LOD report directly from the software (using mean and SD of course).

Glad you find it useful

🤙🤙🤙

Glad to hear that pal

Glad that it helps

You are welcome

Thanks for your comment. In excel when you type CV * P / R / T it’s the same as CV * P / (R*T) so the one I did was actually correct.

Glad it was helpful ! Let me know if you have any problems when trying on your own.

Glad you find it useful.

Thanks for watching buddy

My pleasure ! Let me know if you have any questions

Hi, a simple way to think of “level” is a storage of a number of compounds, the concentration of each compound and the response (area or height) of each compound. So if you plan to build a calibration table with only one level, all of your compounds of interest should be included in this level. If you build a multiple level calibration table, you can have some or all compounds in level 1, some or all compounds in level 2...It’s a bit confusing to describe so i think it’s best if you can share exactly how many compounds you want to add to calibration table and the list of your calibration standards then i will be able to give you a more precise way to set up the calibration table.

@@LearningbyDoingwithPeterTran thank you sir 🙏🙏🙏

Can you explain how to add A control sample in to a already method

@@TherealSunshyne Do you mean to have the method flagged out a control sample that fails your predefined acceptance criteria ? If so that gotta be something to do with Intelligent Reporting. Also let me know which software version you are using.