Thermoionic detector

FTD Flame thermoionic detector HEN High-efficiency nebuliser... 

The sample extract is analyzed by GC-NPD and/or GC/MS. Other GC detectors, as mentioned earlier, may be used instead of NPD. If low detection level is desired, quantitation should be done from the GC analysis. The presence of ary analyte found in the sample must be confirmed on an alternate GC column or preferably by GC/MS. If a thermoionic detector is used and if the sample extract is to be analyzed without any cleanup, it is necessary to exchange the solvent from methylene chloride to methanol. 

Detectors can also be grouped into concentration-dependent detectors and mass-flow-dependent detectors. Detectors whose responses are related to the concentration of solute in the detector cell, and do not destroy the sample, are called concentration-dependent detectors, whereas detectors whose response is related to the rate at which solute molecules enter the detector are called mass-flow-dependent detectors. Typical concentration-dependent detectors are TCD and GC-FTIR. Important mass-flow-dependent detectors are the FID, thermoionic detector for N and P (N-, P-FID), flame photometric detector for S and P (FPD), ECD, and selected ion monitoring MS detector. 

Analytical Procedures. Gas chromatographic (GC) analyses of EPTC and metabolites were performed using glass columns containing 5% carbowax 20M on Chrom WHP and 3% OV-17 on Supelcoport (100/200 mesh). A Varian 3700 gas chromatograph with a nitrogen specific thermoionic detector was used. 

GC has high sensitivity and a good separation efficiency down to very low levels for 1,3,5-triazines. They can be determined by a thermoionization detector <88MI 6l2-02>. GC with an atomic emission detector can also be used <90JC131>. 

Atomic emission detector (AED), electrochemical detection (ELCD), electron capture detection (ECD), evaporative light scattering detector (ELSD, including condensation nuclea-tion-CN), fluorescence detector (FLD, including laser-induced fluorescence), inductively coupled plasma-mass spectormetry (ICP-MS), mass spectrometry (MSD), MS/MS, MS(n), thermoionic detector (NPD), spectrometric detection (UV, Vis, DAD) ... 

Thermoionic Detector in Gas Chromatography for the Determination of Eleven Benzodiazepine Derivatives Commercialized in France. II. Determination of Clonazepam in Human Serum Bull. Soc. Pharm. Bordeaux 118(1-2) 26-36 (1979) CA 92 174110a... 

Paradoxically, the gas-density detector, which can supply the molecular mass of an unknown, can be considered to be a selective detector in gas chromatography (58). This comment effectively illustrates the dearth of convenient selective detectors. At best such detectors help to identify compounds that contain halogen atoms (electron-capture or thermoionic detectors), sulfur, nitrogen, or phosphorus (flame-photometric or thermoionic detectors). Physiological detectors have also been used in certain rare cases (insects that react to sexual pheromones, for example, or the chemist s nose, a dangerous and hazardous application). 

As mentioned before, a unique advantage of SFC is the fact that a wide variety of detection methods can be applied (see Table 11). Besides the traditional LC detection (e.g., UV) the use of GC detectors, especially, enables relatively sensitive, universal (FID), as well as selective [e.g.. electron capture detectors (BCD), thermoionic detectors (TID)] methods of detection. 

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