Chromatography Forum

HI

Can any one share the Determination of dimethylphoxide by Head space GC method.

Thanks in advance

Ganapathi

Dimethylsulfoxide is a high boiling (189 C) , small volatule , viscous liquide.
They dont quantity estimated by HeadSpace method.

Dear Mr. Ganapathy we can do the analysis of DMSO in Headspace by using the N-Dimethyl imidazolidinone as solvent follow the high boiler headspsce method.Sample oven : 120°C, Needle: 130°C and Transfer line use : 150°C.

Regards
A.Kalidass

Hi

Well think DMSO has an even higher boiling point 189°C, so if you use a headspace with loop injection like an Agilnet I would recommend even higher temperatures in needle/loop/t-line ~200°C.

DMSO is miscible in water so you can used that instead of DMI depending if it suits your sample and/or potential other solvents.

For trace analysis (5000ppm or below) of residual solvents in for instance drug substances GC-Headspace is not uncommon, but for higher consentrations I would consider a different injection technique.

There are generic methods in the pharmacopieas like Ph Eur chapter 2.4.24 or USP chapter <467> that could be used as a starting point for development , if you do not have acess to those, just google residual solvents, perhaps add USP or Ph Eur and you should find a bunch of articles or even published applications that can be useful.

What is the matrix of the samples ?

Peter

Hi,

We tried in agilent Head space GC with high temepratures diluent as DMI, but we are not getting %RSD with in<15, some times comming in >15% and some times <15%

Regards,

Ganapathi

Hi
So it should be. DMSO is usually extracted with water and injected as a liquid aqueous solution.

If you have low levels of DMSO and you have bare metal components in your HS analyzer you WILL have poor RSD values.

You must have deactivated fused silica components for all surfaces which come in contact with the DMSO.

Also if you can melt your matrix at a temperature your vial septum and valve rotor can handle don't even use a dissolution solvent, just melt your matrix and do headspace.

This is one example where I prefer to use the PE system which uses timed injection and which has very inert sample contact surfaces.

best wishes,

Rod

A method for routinely determination of dimethyl sulfoxide (DMSO) and dimethyl sulfone (DMSO2) in human urine was developed using gas chromatography-mass spectrometry. The urine sample was treated with 2,2-dimethoxypropane (DMP) and hydrochloric acid for efficient removal of water, which causes degradation of the vacuum level in mass spectrometer and shortens the life-time of the column. Experimental DMP reaction parameters, such as hydrochloric acid concentration, DMP-urine ratio, reaction temperature and reaction time, were optimized for urine. Hexadeuterated DMSO was used as an internal standard. The recoveries of DMSO and DMSO2 from urine were 97-104 and 98-116%, respectively. The calibration curves showed linearity in the range of 0.15-54.45 mg/L for DMSO and 0.19-50.10 mg/L for DMSO2. The limits of detection of DMSO and DMSO2 were 0.04 and 0.06 mg/L, respectively. The relative standard deviations of intra-day and inter-day were 0.2-3.4% for DMSO and 0.4-2.4% for DMSO2. The proposed method may be useful for the biological monitoring of workers exposed to DMSO in their occupational environment.


I hope it helps well

Hi Samihat

Can we have the reference to this paper please.

Peter