Nitrogen detector

For analysis, white phosphoms is typically extracted through a fritted thimble with refluxed toluene. Any trace amounts of water are captured in a cahbrated sidearm to the apparatus. The soflds on the frit are weighed, the water measured, and the phosphoms calculated by difference. For impure samples of phosphoms, the toluene extract may be analy2ed with a gas chromatograph (gc) equipped with a phosphoms—nitrogen detector. 

An automated log P workstation using a shake-flask method and robotic liquid handling in 96-well plate format is commercially available [30]. The system is equipped with a diode-array spectrophotometer and equimolar nitrogen detector. 

Supercritical fluid chromatography (SEC) was first reported in 1962, and applications of the technique rapidly increased following the introduction of commercially available instrumentation in the early 1980s due to the ability to determine thermally labile compounds using detection systems more commonly employed with GC. However, few applications of SEC have been published with regard to the determination of triazines. Recently, a chemiluminescence nitrogen detector was used with packed-column SEC and a methanol-modified CO2 mobile phase for the determination of atrazine, simazine, and propazine. Pressure and mobile phase gradients were used to demonstrate the efficacy of fhe fechnique. 

CLND Chemiluminescence nitrogen detector Pyro-chemiluminescence... 

Aqueous simulants — HPLC with UV detection. Olive oil extracted with dilute sodium hydrogen carbonate and the aqueous extract acidified and examined by HPLC Headspace GC with automated sample injection and specific nitrogen detector. Confirmation by GC-MS if required Headspace GC of the polymer dissolved in N,N-dimethylacetamide. 

Bhattachar, S.N., Wesley, J.A., and Seadeek, C. 2006. Evaluation of the chemiluminescent nitrogen detector for solubility determinations to support drug discovery. J. Pharm. Biomed. Anal. 41 152. 

Another difficulty in the gas chromatographic separation of amino acids is the choice of detector and it may be necessary to split the gas stream and use two different detectors. The flame ionization detector, which is commonly used, is non-specific and will detect any non-amino acid components of the sample unless purification has been performed prior to derivatization. In addition the relative molar response of the flame ionization detector varies for each amino acid, necessitating the production of separate standard curves. As a consequence, although gas chromatography offers theoretical advantages, its practical application is mainly reserved for special circumstances when a nitrogen detector may be useful to increase the specificity. 

Report of the Project Definition Study on the Nitrogen Detector System, TRIUMF, Vancouver, BC, Canada, July 1992. 

Yan, B. Zhao, J. Leopold, K. Zhang, B. Jiang, G. Structure-Dependent Response of a Chemiluminescence Nitrogen Detector for Organic Compounds with Adjacent Nitrogen Atoms Connected by a Single Bond. Anal. Chem. 2007, 79, 718-726. 

Kelly, T. J. Modifications of Commercial Oxides of Nitrogen Detectors for Improved Response Brookhaven National Laboratory Upton, NY, 1986 BNL Informal Report 38000 pp 1-31. 

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

R. Hall, The nitrogen detector in gas chromatography, part III, electrochemical detectors, CRC Crit. Rev. Anal. Chem., 7 345-363 (1978). 

FIGURE 10.2 Mechanism for the chemiluminescent nitrogen detector. R = any group attached to a nitrogen. 

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