A simple, rapid and accurate method for the determination of monoethanolamine (MEA) in PHWR steam-water circuits has been developed. MEA is added in the feed water to provide protection against corrosion while hydrazine is added to scavenge dissolved oxygen. The quantitative determination of MEA in presence of hydrazine was accomplished using derivatization ion chromatography with conductometric detection in nonsuppressed mode. A Metrosep cation 1-2 analytical column and a Metrosep cartridge were used for cation separation. A mixture of 4？mM tartaric acid, 20% acetone and 0.05？mM HNO3 was used as eluent. Acetone in the mobile phase leads to the formation of different derivatives with MEA and hydrazine. The interferences due Na+ and NH4？+ were eliminated by adopting a simple pretreatment procedure employing OnGuard-H cartridge. The limit of detection limit of MEA was 0.1？μg？mL？1 and the relative standard deviation was 2% for the overall method. The recovery of MEA added was in the range 95%–102%. The method was applied to the determination of MEA in steam generator water samples. 1. Introduction In Indian pressurized heavy water reactors (IPHWRs), the nuclear heat is transported by the heavy water (D2O) coolant in the primary heat transport system to the secondary light water (H2O) for steam production. In the steam-water circuit, two-phase erosion corrosion is a serious operational issue. To provide protection against the corrosion, volatile amines are added in the feed water of steam generators (SG) to raise the pH of the water. These amines volatilize along with the steam and are partly carried away to the turbine and condenser part, thereby providing protection against corrosion to the entire steam-water circuit. Along with amine, hydrazine is injected to scavenge dissolved oxygen, and thereby produce reducing conditions. The treatment is called as an all volatile treatment (AVT), and the amines are used as AVT reagents [1–3]. Ammonia (earlier used) was replaced by cyclohexylamine and morpholine as AVT reagents because of their less volatility [3, 4]. This change allowed the pH of the steam condensate from the turbine cycle to be increased to a level that significantly reduced flow-assisted corrosion. MEA, because of its less volatility and higher base strength, has eventually replaced cyclohexylamine and morpholine [5–7]. Quantification of MEA is an essential step in determining its appropriate amount to use for maximal protection. The accurate and reliable determination of MEA in the presence of hydrazine is a challenging analytical problem because
References
[1]
T. O. Passell, C. S. Welty, and S. A. Hobart, “Use of organic amines in water chemistry control for pressurized water reactor secondary systems,” Progress in Nuclear Energy, vol. 20, no. 3, pp. 235–254, 1987.
[2]
H. Namduri, Formation and quantification of corrosion deposits in the power industry, Ph.D. thesis, University of North Texas, 2007.
[3]
A. G. Kumbhar, S. V. Narasimhan, and P. K. Mathur, “Spectrophotometric method for determination parts per million levels of cyclohexylamine in water,” Talanta, vol. 47, no. 2, pp. 421–437, 1998.
[4]
R. Gilbert, R. Rioux, and S. E. Saheb, “Ion chromatographic determination of morpholine and cyclohexylamine in aqueous solutions containing ammonia and hydrazine,” Analytical Chemistry, vol. 56, no. 1, pp. 106–109, 1984.
[5]
M. J. Fountain and I. Smiesco, “Computer modeling the potential benefits of amines in NPP Bohunice secondary circuit,” in Proceedings of JAIF International Conference on Water Chemistry in Nuclear Power Plants- Operational Experience and New Technologies for Management, pp. 315–320, Tokyo, Japan, 1988.
[6]
N. Higuchi, M. Ito, M. Nakamura, Y. Shiroyama, and T. Matsui, “Over view of use of ethanolamine in Mihama Unit 2,” in Proceedings of JAIF International Conference on Water Chemistry in Nuclear Plants, pp. 599–602, Kashiwazaki, Japan, 1998.
[7]
T. O. Passell, “Use of on-line ion chromatography in controlling water quality in nuclear power plants,” Journal of Chromatography A, vol. 671, no. 1–2, pp. 331–337, 1994.
[8]
Application Note 39: Determination of Ethanolamines in Refinery Water, Dionex, Sunnyvale, Calif, USA, 1990.
[9]
Application Update 138: Determination of Ethanolamines in Industrial Waters by Cation-Exchange Chromatography, Dionex, Sunnyvale, Calif, USA, 1998.
[10]
IC Application Note No. C-78: Ethanolamines Besides Alkali and Alkaline Earth Metal Cations, Metrohm, Herisau, Switzerland, 2004.
[11]
Metrohm IC Application Note No. C-107: Hydoxylamine, Ethanolamine, Triethanolamine and Hydrazine on the Metrosep C3-250 Cation Column, Metrohm, Herisau, Switzerland, 2008.
[12]
R. Kadnar, “Determination of amines used in the oil and gas industry (upstream section) by ion chromatography,” Journal of Chromatography A, vol. 850, no. 1–2, pp. 289–295, 1999.
[13]
O. Mrklas, A. Chu, and S. Lunn, “Determination of ethanolamine, ethylene glycol and triethylene glycol by ion chromatography for laboratory and field biodegradation studies,” Journal of Environmental Monitoring, vol. 5, no. 2, pp. 336–340, 2003.
[14]
R. Daigle, M. C. Mehra, and V. Mallet, “Single column ion chromatography of ammonium ion, alkali metals and alkyl amines,” Chromatographia, vol. 32, no. 3–4, pp. 143–147, 1991.
[15]
D. Bostic, G. Burns, and S. Harvey, “Qualitative corrosion monitoring by on-line ion chromatography,” Journal of Chromatography, vol. 602, no. 1–2, pp. 163–171, 1992.
[16]
B. M. De Borba, M. Laikhtman, and J. S. Rohrer, “Determination of sodium at low ng/l concentrations in simulated power plant waters by ion chromatography,” Journal of Chromatography A, vol. 995, no. 1–2, pp. 143–152, 2003.
[17]
M. D. H. Amey and D. A. Bridle, “Application and development of ion chromatography for the analysis of transition meta cations in the primary coolants of light water reactors,” Journal of Chromatography A, vol. 640, no. 1–2, pp. 323–333, 1993.
[18]
J. C. Green and R. M. Donaldson, “The role played by ion chromatography in the assessment of amines for two-phase erosion corrosion control in nuclear electric's steam-water circuits,” Journal of Chromatography A, vol. 640, no. 1–2, pp. 303–308, 1993.
[19]
S. Saba, J. A. Ciaccio, J. Espinal, and C. E. Aman, “Synthesis and NMR spectral analysis of amine heterocycles: the effect of asymmetry on the H and C NMR spectra of N,O-acetals,” Journal of Chemical Education, vol. 84, no. 6, pp. 1011–1013, 2007.
[20]
J. R. Holtzclaw, S. L. Rose, J. R. Wyatt, D. P. Rounbehler, and D. H. Fine, “Simultaneous determination of hydrazine, methylhydrazine, and 1,1-dimethylhydrazine in air by derivatization/gas chromatography,” Analytical Chemistry, vol. 56, no. 14, pp. 2952–2956, 1984.
