Chromatography Forum

Hello,
I'm trying to determine the following pesticides:
-Thiram;
-Azadirachtin;
-Pyrethrins.
What are your favourites MS/MS settings for these molecules?
I mean:
-MRM Transitions;
-Cone Voltage
-Collision energy.
I'm talking about LC/MS-MS.
I know that pyrethrins are usually made by GC/MS-MS but I found some bibliography about the possibility of doing them by LC system.

Thank you so much

Dear Zelda855,

I've got the MRM Transitions for you. I don't have the other things you asked for. My experience is that this is different per machine although you should find something on the internet.

Azadirachtine, C35H44O16, ESI+, 738>703 738>685 738>585, [M+NH4]+
Thiram, C6H12N2S4, ESI+, 241>88 241>120 241>196, [M+H]+
Pyrethrins, Cinerin I, C20H28O3, ESI+ , 317>107 317>149 / 334,2>107,0 334,2>149,0
Pyrethrins, Cinerin II, C21H28O5, 361>107 361>149 / 378,2>107,0 378,2>149,1
Pyrethrins, Jasmolin I, C21H30O3, ESI+, 331>107 331>163 / 348,3>163,2 348,3>107,0
Pyrethrins, Jasmolin II, C22H30O5, ESI+, 375>107 375>163 / 392,2>163,1 392,2>107,1
Pyrethrins, Pyrethrin I, C21H28O3, ESI+, 329>133 329>161 / 346,2>161,2 346,2>133,1
Pyrethrins, Pyrethrin II, C22H28O5, ESI+, 373>133 373>161 / 390,2>161,1 390,2>133,1

Which transitions you use also depends on your machine. But at least you have a hint. The sensitivity of the Pyrethrins are not known to me so I think it will be low. But at least you tried, right?

Good luck with it.

Regards,

Wouter de Graaf