Limit of Detection of13C Using an Atomic Emission Detector (MIP) Coupled to Gas Chromatography

This paper presents the capability of using molecules labelled with 13 C and of measuring them by gas chromatography coupled to an MIP. The sensitivity of the detection of this stable carbon isotope has been optimised using non steroid anti inflammatory drugs such as Fenoprofen, Flurbiprofen, Ketoprofen and Diclofenac and applying a four factors experimental design. This work shows that the main factors acting on the sensitivity of the 13 C detection are the flow rates of hydrogen and helium (plasma gas). The linearity was demonstrated in the range from 50 to 300 pg of 13 C. The limit of detection calculated according to various methods (IUPAC, Oppenheimer and Quimby - Sullivan) gave the following results: 2 pg/μl, 12 pg/μl and 0.1 pg/s respectively. These results show that 13 C atomic emission is quite a specific and sensitive mode of detection of 13 C labelled molecules after gas chromatographic separation.