Dear respected professors, doctors and researchers
I am planning to collect environmental samples (food, water and sediment samples) to analyze existence of some POPs like phthalates and OCPs using GC MS but without adding internal standards to the extracted samples because of the difficulty of obtaining stock solution in the local (Sudan) market. That is, I am unable to get internal standards (solution) in Sudan to use it with GC MS analysis. So if I learned any way of interpreting chromatograms of samples with no ISTD it will be very helpful
If any one can guide me or even suggest to me a specific reference for this.
sincerely
Dr. Mohammed Osman Ali
uofk
Dept. of Environmental Health
TTDearDTry to prepare the standestandard from avillavailable sources
Mr. Ali,
You can use the ratio m/z and intensity to obtain a linear range. Within this linear range you can quantify.
If proper internal standards are not available, then you can do the quantification by external standard method. For this, you should have the standards of the target compounds that are to be quantified.
In case you are unable to use internal std you can opt to use external std and make data interpretation using stds calibration