It is very strange, especially because you are using the deuterated IS. Have you ever tried to optimize simulatenously the optimal concentration range for 3MCPD-d5 and 3MCPD. You can see how to do it in some of my publications (e.g., Journal of Chromatography A, 1121, 2006:99–105). It helps a lot and saves time. If you any have further question on how to do it, do not hesitate to contact me.

I think you will have to provide some more information. What mass did you select for the deuterated ion in SIM mode? You may have to optimize this. Don't just assume that their fragmentation will follow a similar pattern. There are few times the deuterated analogues may show different base molecule. Let us have some more details. I hope my initial suggestion helps.

Thank you all

For 3MCPD the ions are 91,147,196 and 198

For 3MCPD-d5 the ions are 150,201 and 203

I'm not too sure why you decided to use 20% NaCl solution was solvent system for dissolving your compound? Is your IS stable in water? What type of column are you using? GC method? NOTE: Salts are not good for GC-MS or GC in general.

I am following a Austrian method for the detection of 3MCPD in food.

I had received it three weeks ago

It is mentioned in the method to use 20% NaCl for the dilution of 3MCPD standard

Anyway I had found my mistake

In the method I had input the start time of the detector @ 0 min and the end time @ 3,00 while my ions start to appear @ 10,813

stupid mistake

now everything is O.K after correcting the time

Thank you all for participating

How do you derivative your 3-MCPD? I am trying to set up this method using MS 5975 but I don't detect the molecular ion after derivitisation with HFBI.

Hi Ndumiso,

I have validated a 3-MCPD method on soy matrix by varian GC/MS/MS ion trap. I extracted 3-MCPD and the internal standard 3-MCPD d5 into ethyl ether then reconditioned with 2,2-4 trimethylpentane and derivitised with 0.05 mL of HFBI at 75 degree for 25 minutes. 3-MCPD ions are 253, 275, 289. I used AOAC 2000.1 as my reference method.

Hi Ndumiso,

Sorry for the delay to answer your request I was on vacation for 9 days.

I prepare my derivatization by 1 gm Phenylboronic + 4 ml acetone/water mix 19:1 v/v.

Then derivatise @ 90 oC for 20 min.

3-MCPD ions are 147, 196 and 198 and 3-MCPD-d5 ions are 150, 201 and 203.

Thank you for Mohammad and Kaiser for your responses. Some scientist told me that I won't be able to get low sensitivty and the molecular ion as I am using an electron impact (EI) ionisation with diffusion pump system and what I need is a Negative Chemical Ionisation (NCI) with a turbo pump. What is you take on this?

I am actively engaged in 3-mcpd method development. I recently found our old procedure was deficient (namely recovery from the diatomaceous earth columns). I have just fixed the method.

I've found this method

www.chnfood.cn/index.php?m=Download&a=down&id=19033‎

is pretty good though for dry HVP's I dissolve 2g + 10g 5N NaCl vortex, sonicate centriguge then add a weighed 3ml portion of the supernatant to each of two SPE columns and elute each with 15ml 10% ethyl ether 90% ethyl acetate. We then blow down to 1ml with N2 over Na2SO4 transfer to a new tube add 4ml hexanes, and 100ul HFBI, react 15 min Room Temp, then remove HFBI by extracting 3X with water. Then the sample is blown back down to 1ml again and injected. We also use 3-methoxy-1,2 propane diol as the ITSD added right after elution from the column (it binds irreversibly if added before). We use a DB-5 though I saw a reference for innowax.

I am also currently looking at using the shorter phenyl boric acid method but am finding it is very sensitive to liner and active site issues. I am seeing some pretty bad tailing and the resolution between our ITSD 3-methoxy-1,2 propane diol and 3-mcpd is not great on a db-5. I've read a few papers that reference using a db-1 but I believe the resolution will be even worse because the phenyl groups probably interact with the phenyl stationary phase on the db-5. Perhaps a higher phenyl column like a db-20, 35, 50, or 17 would do better but I have seen no references for anything other than db-1 or db-5.