Flow injection conductometric system with gas diffusion separation for the determination of Kjeldahl nitrogen in milk and chicken meat

A simple flow injection (FI) conductometric system with gas diffusion separation was developed for the determination of Kjeldahl nitrogen (or proteins) in milk and chicken meat. The sample was digested according to the Kjeldahl standard method and the digest was diluted and directly injected into th...

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Main Authors: Jaroon Junsomboon, Jaroon Jakmunee
Format: Journal
Published: 2018
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http://cmuir.cmu.ac.th/jspui/handle/6653943832/60144
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Institution: Chiang Mai University
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spelling th-cmuir.6653943832-601442018-09-10T03:42:49Z Flow injection conductometric system with gas diffusion separation for the determination of Kjeldahl nitrogen in milk and chicken meat Jaroon Junsomboon Jaroon Jakmunee Biochemistry, Genetics and Molecular Biology Chemistry Environmental Science A simple flow injection (FI) conductometric system with gas diffusion separation was developed for the determination of Kjeldahl nitrogen (or proteins) in milk and chicken meat. The sample was digested according to the Kjeldahl standard method and the digest was diluted and directly injected into the donor stream consisting of 4 M NaOH. In alkaline medium, ammonium was converted to ammonia, which diffused through the PTFE membrane to dissolve in an acceptor stream (water). Dissociation of ammonia caused a change in conductance of the acceptor solution, which was linearly proportional to the concentration of ammonium originally present in the injected solution. A conductometric flow through cell and an amplifier circuit was fabricated, which helped improve sensitivity of the conductometric detection system. With using a plumbing Teflon tape as a gas diffusion membrane and without thermostating control of the system, a linear calibration graph in range of 10-100 mg L-1N-NH4was obtained, with detection limit of 1 mg L-1and good precision (relative standard deviation of 0.3% for 11 replicate injections of 50 mg L-1N-NH4). The developed method was validated by the standard Kjeldahl distillation/titration method for the analysis of milk and chicken meat samples. The proposed system had sample throughput of 35 h-1and consumed much smaller amounts of chemical than the standard method (275 mg vs 17.5 g of NaOH per analysis, respectively). © 2008 Elsevier B.V. All rights reserved. 2018-09-10T03:38:38Z 2018-09-10T03:38:38Z 2008-10-10 Journal 00032670 2-s2.0-52049110787 10.1016/j.aca.2008.08.012 https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=52049110787&origin=inward http://cmuir.cmu.ac.th/jspui/handle/6653943832/60144
institution Chiang Mai University
building Chiang Mai University Library
country Thailand
collection CMU Intellectual Repository
topic Biochemistry, Genetics and Molecular Biology
Chemistry
Environmental Science
spellingShingle Biochemistry, Genetics and Molecular Biology
Chemistry
Environmental Science
Jaroon Junsomboon
Jaroon Jakmunee
Flow injection conductometric system with gas diffusion separation for the determination of Kjeldahl nitrogen in milk and chicken meat
description A simple flow injection (FI) conductometric system with gas diffusion separation was developed for the determination of Kjeldahl nitrogen (or proteins) in milk and chicken meat. The sample was digested according to the Kjeldahl standard method and the digest was diluted and directly injected into the donor stream consisting of 4 M NaOH. In alkaline medium, ammonium was converted to ammonia, which diffused through the PTFE membrane to dissolve in an acceptor stream (water). Dissociation of ammonia caused a change in conductance of the acceptor solution, which was linearly proportional to the concentration of ammonium originally present in the injected solution. A conductometric flow through cell and an amplifier circuit was fabricated, which helped improve sensitivity of the conductometric detection system. With using a plumbing Teflon tape as a gas diffusion membrane and without thermostating control of the system, a linear calibration graph in range of 10-100 mg L-1N-NH4was obtained, with detection limit of 1 mg L-1and good precision (relative standard deviation of 0.3% for 11 replicate injections of 50 mg L-1N-NH4). The developed method was validated by the standard Kjeldahl distillation/titration method for the analysis of milk and chicken meat samples. The proposed system had sample throughput of 35 h-1and consumed much smaller amounts of chemical than the standard method (275 mg vs 17.5 g of NaOH per analysis, respectively). © 2008 Elsevier B.V. All rights reserved.
format Journal
author Jaroon Junsomboon
Jaroon Jakmunee
author_facet Jaroon Junsomboon
Jaroon Jakmunee
author_sort Jaroon Junsomboon
title Flow injection conductometric system with gas diffusion separation for the determination of Kjeldahl nitrogen in milk and chicken meat
title_short Flow injection conductometric system with gas diffusion separation for the determination of Kjeldahl nitrogen in milk and chicken meat
title_full Flow injection conductometric system with gas diffusion separation for the determination of Kjeldahl nitrogen in milk and chicken meat
title_fullStr Flow injection conductometric system with gas diffusion separation for the determination of Kjeldahl nitrogen in milk and chicken meat
title_full_unstemmed Flow injection conductometric system with gas diffusion separation for the determination of Kjeldahl nitrogen in milk and chicken meat
title_sort flow injection conductometric system with gas diffusion separation for the determination of kjeldahl nitrogen in milk and chicken meat
publishDate 2018
url https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=52049110787&origin=inward
http://cmuir.cmu.ac.th/jspui/handle/6653943832/60144
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