Chromatography Forum

Basically information:
Benzoyl hydrazine was dissolved in Acetone, 2mg/mL, inj. 1.0uL, split: 5:1
column: RTX-1(100% dimethyl polysiloxane),30m*0.52mm*3um
column flow: 4mL/min
Inlet temp.: 200oC carrier gas: Nitrogen Detector: FID Det. temp.: 300cC

Problem: Benzoyl hydrazine always showed a tailing peak and the peak shape become increasingly worse.

Asking for the solution!
If you have any advice, please tell me.

TKS!

MHD,

Immaculate inlet conditions, no wool. For a 0.53 id you can probably can get away with a higher flow rate than what you have now which would help minimize undesired interactions. If you have a thinner film available, you might try that as well. Can you post your temperature program?

Best regards.

Temperature program:
Initial Temp.(oC) *****Hold Time(min)*****Increasing Rate(oC/min)
******60***************** 0*******************20
******270****************10

Benzoyl hydrazine Rt: 9.1min

MHd,

At 60C initial, you are right near the BP of your solvent, acetone. I would try cooler if you can get there (say 42C or 38 C if your lab is cool enough) or hotter (80 or 90), but not 60. If you start at 42, I would also put a 1 minute hold in as well (just me...) At 2 mg/ml you can probably afford to increase your split ratio a bit as well. I also still think you could increase your flow rate a bit, especially if you start cooler.

Best regards.

Thanks AICMM,

I would try and keep updating!

Hi all,

Now, I used Acetone as both sample solvent and derivatizing agent, the residual hydrazine hydrate and benzoyl hydrazine can all be detected by HPLC on C18 column.