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Stacking and analysis of melamine in milk products with acetonitrile-salt stacking technique in capillary electrophoresis.

Kong Y, Wei C, Hou Z, Wang Z, Yuan J, Yu J, Zhao Y, Tang Y, Gao M - J Anal Methods Chem (2014)

Bottom Line: The optimized buffer contains 80.0 mmol/L pH 2.8 phosphates.Melamine could be detected within 20.0 min at +10 kV with a low limit of detection (LOD) of 0.03 μmol/L.Satisfactory reproducibility (inter- and intraday RSD% both for migration time and peak area was lower than 5.0%) and a wide linearity range of 0.05 μmol/L ~ 10.0 μmol/L were achieved.

View Article: PubMed Central - PubMed

Affiliation: Institute of Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Bioengineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.

ABSTRACT
Melamine was measured in real milk products with capillary electrophoresis (CE) based on acetonitrile-salt stacking (ASS) method. Real milk samples were deproteinized with acetonitrile at a final concentration of 60% (v/v) and then injected hydrodynamically at 50 mBar for 40.0 s. The optimized buffer contains 80.0 mmol/L pH 2.8 phosphates. Melamine could be detected within 20.0 min at +10 kV with a low limit of detection (LOD) of 0.03 μmol/L. Satisfactory reproducibility (inter- and intraday RSD% both for migration time and peak area was lower than 5.0%) and a wide linearity range of 0.05 μmol/L ~ 10.0 μmol/L were achieved. The proposed method was suitable for routine assay of MEL in real milk samples that was subjected to a simple treatment step.

No MeSH data available.


Influence of buffer concentrations on theoretical plate numbers, influences of NaCl concentration on Rs and migration times.
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fig2: Influence of buffer concentrations on theoretical plate numbers, influences of NaCl concentration on Rs and migration times.

Mentions: The influence of buffer concentration, ranged from 20.0 mmol/L to 140.0 mmol/L, on stacking was investigated (Figure 2). Theoretically, to some extent, higher buffer concentration provided larger conductivity difference between buffer and sample zone, which in turn might perform better primary stacking effect. In our works, stacking could not take place at the low buffer concentration (<40 mmol/L), as the conductance of the buffer was similar to that of the sample zone, the difference of migrating velocity of the MEL in buffer and in sample zone was not large enough to initiate stacking. When buffer concentration was higher than 40.0 mmol/L, stacking phenomena occurred. As the buffer concentration increased, the theoretical plate number (N) increased firstly followed by decreasing when the concentration was higher than 80.0 mmol/L, which may heat due to the broaden effects of extra Joule. Finally, a concentration of 80.0 mmol/L was selected for further studies.


Stacking and analysis of melamine in milk products with acetonitrile-salt stacking technique in capillary electrophoresis.

Kong Y, Wei C, Hou Z, Wang Z, Yuan J, Yu J, Zhao Y, Tang Y, Gao M - J Anal Methods Chem (2014)

Influence of buffer concentrations on theoretical plate numbers, influences of NaCl concentration on Rs and migration times.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4150491&req=5

fig2: Influence of buffer concentrations on theoretical plate numbers, influences of NaCl concentration on Rs and migration times.
Mentions: The influence of buffer concentration, ranged from 20.0 mmol/L to 140.0 mmol/L, on stacking was investigated (Figure 2). Theoretically, to some extent, higher buffer concentration provided larger conductivity difference between buffer and sample zone, which in turn might perform better primary stacking effect. In our works, stacking could not take place at the low buffer concentration (<40 mmol/L), as the conductance of the buffer was similar to that of the sample zone, the difference of migrating velocity of the MEL in buffer and in sample zone was not large enough to initiate stacking. When buffer concentration was higher than 40.0 mmol/L, stacking phenomena occurred. As the buffer concentration increased, the theoretical plate number (N) increased firstly followed by decreasing when the concentration was higher than 80.0 mmol/L, which may heat due to the broaden effects of extra Joule. Finally, a concentration of 80.0 mmol/L was selected for further studies.

Bottom Line: The optimized buffer contains 80.0 mmol/L pH 2.8 phosphates.Melamine could be detected within 20.0 min at +10 kV with a low limit of detection (LOD) of 0.03 μmol/L.Satisfactory reproducibility (inter- and intraday RSD% both for migration time and peak area was lower than 5.0%) and a wide linearity range of 0.05 μmol/L ~ 10.0 μmol/L were achieved.

View Article: PubMed Central - PubMed

Affiliation: Institute of Mitochondrial Biology and Medicine, The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Department of Bioengineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.

ABSTRACT
Melamine was measured in real milk products with capillary electrophoresis (CE) based on acetonitrile-salt stacking (ASS) method. Real milk samples were deproteinized with acetonitrile at a final concentration of 60% (v/v) and then injected hydrodynamically at 50 mBar for 40.0 s. The optimized buffer contains 80.0 mmol/L pH 2.8 phosphates. Melamine could be detected within 20.0 min at +10 kV with a low limit of detection (LOD) of 0.03 μmol/L. Satisfactory reproducibility (inter- and intraday RSD% both for migration time and peak area was lower than 5.0%) and a wide linearity range of 0.05 μmol/L ~ 10.0 μmol/L were achieved. The proposed method was suitable for routine assay of MEL in real milk samples that was subjected to a simple treatment step.

No MeSH data available.