Nitrogen-specific chemiluminescence detectors

A nitrogen-specific chemiluminescence detector exists that is very similar to the SCD. The effluent from a column enters a combustion tube with a stainless-steel... 

C12/C14 monoethanolamide, methyl neodecanamide, and JV-methyl C12/C14 glucosa-mides were determined in cleaning formulations by chromatography on Ci) with 80 20 or 75 25 methanol/water, using a nitrogen-specific chemiluminescence detector (156). 

Fujinari EM, Courthaudon LO. Nitrogen-specific liquid-chromatography detector based on chemiluminescence—Application to the analysis of ammonium nitrogen in waste-water. Journal of Chromatography 592, 209-214, 1992. 

Nitric oxide release from blood vessels was first detected by chemiluminescence (Palmer et ai, 1987). In the original adaptations of the nitric oxide detector, perfusates from isolated vessels were directly mixed in a reflux chamber containing acetic acid and iodine. The iodine in the reflux chamber served to reduce any nitrites or nitroso-containing groups to nitric oxide, which was stripped from the chamber by a continuous stream of nitrogen or helium that flowed to the chemiluminescent detector. Replacement of the acetic acid with the less volatile trichloroacetic acid reduces problems with contamination of the nitric oxide detector (Dr. D. Harrison, Emory University, Atlanta, Georgia, personal communication, 1991). While extremely sensitive, the use of the acid reflux chamber also reduces the specificity of the assay, raising questions as to whether nitric oxide or a nitrosothiol is EDRF (Myers et ai, 1990). 

EM Fujinari, JD Manes. Nitrogen-specific detection of peptides in liquid chromatography with chemiluminescent nitrogen detector. J Chromatogr A 676 113-120, 1994. 

Nussbaum MA, Baertschi SW, Jansen PJ. Determination of relative UV response factors for HPLC by use of a chemiluminescent nitrogen-specific detector. J Pharm Biomed Anal 2002 27 983-993. 

The oldest chemiluminescent detector was the thermal energy analyzer (TEA), which was specific for N-nitroso compounds. N-nitroso compounds such as nitrosamines are catalytically pyrolyzed and produce nitric oxide which reacts with ozone to produce nitrogen dioxide in the excited ] state, which decays to the ground state with the emission of a photon. A photomultiplier in the reaction chamber measures the emission. Nitrosodi-methylamines have been detected to about 30-40 pg [108]. 

Fujinary E, Manes JD, Bizanek R, Peptide content determination of crude synthetic peptides by reversed-phase liquid chromatography and nitrogen-specific detection with a chemiluminescent nitrogen detector, J. Chromatogr A, 743 85-89, 1996. 

Element selective detectors Element selective detectors applicable in pesticide residue analysis include electron capture detector (ECD), electrolytic conductivity detector (ELCD), halogen-specific detector (XSD), nitrogen phosphorus detector (NPD), flame photometric detector (FPD), pulsed flame photometric detector (PEPD), sulfur chemiluminescence detector (SCD), and atomic emission detector (AED). To cover a wider range of pesticide residues, a halogen-selective detector (ECD, ELCD, XSD) in conjvmction with a phosphorus- (NPD, FPD), nitrogen- (NPD), and/or sulfur-selective detector (FPD, SCD) is commonly used. A practical approach is to spht the column flow to two detectors that reduces the number of injections however, the reduced amoimt of analyte that reaches the detector must be considered. 

There are a number of other GC detectors commercially available. Photoionization detectors (PIDs) are primarily used for the selective, low-level detection of the compounds which have double or triple bonds or an aromatic moiety in their structures. Electrolytic conductivity detectors (ELCDs) are used for the selective detection of chlorine-, nitrogen-, or sulfur-containing compounds at low levels. Chemiluminescence detectors are usually employed for the detection of sulfur compounds. The atomic emission detectors (AEDs) can be set up to respond only to selected atoms, or group of atoms, and they are very useful for element-specific detection and element-speciation work. 

Selective GC detectors aid in the detection and identification of compounds containing specific elements halogens with electron capture detector (BCD) or electrolytic conductivity detector (ELCD) nitrogen and phosjAorus with nitrogen-phosphorus detector (NPD) sulfur and phosphorus with flame photometric detector (FPD) and sulfur with sulfur chemiluminescence detector (SCD). The development of the atomic... 

Recent applications of HTO method for organic nitrogen analysis have been proposed for total nitrogen analyzers alone as well as for combined analyzers of DOC and DON. These instruments are stand-alone commercial analyzers or hybrid organic carbon/nitrogen analyzers equipped with online chemiluminescent detectors, sometimes adapted to the specific characteristics of the water samples. 

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