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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.


Related in: MedlinePlus

Electropherograms of real milk samples under optimized condition. (A)/(B)/(C) were samples from YILI pure milk; (D) was from WANGZAI reconstituted milk. Samples were treated with 60% acetonitrile (v/v) and were injected hydrodynamically at 50 mBar for 40 s. All samples also contained 8 mmol/L pH 2.8 phosphate solution and partial samples were added with MEL ((B)/(C) 0.5 μmol/L; (D) 8 μmol/L). Stacking was performed under +10.0 kV and results were detected at 200.0 nm.
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fig6: Electropherograms of real milk samples under optimized condition. (A)/(B)/(C) were samples from YILI pure milk; (D) was from WANGZAI reconstituted milk. Samples were treated with 60% acetonitrile (v/v) and were injected hydrodynamically at 50 mBar for 40 s. All samples also contained 8 mmol/L pH 2.8 phosphate solution and partial samples were added with MEL ((B)/(C) 0.5 μmol/L; (D) 8 μmol/L). Stacking was performed under +10.0 kV and results were detected at 200.0 nm.

Mentions: The proposed method was applied to real milk samples. Separation and stacking results of two bands of milk products (YILI pure milk and WANGZAI reconstituted milk) were shown in Figure 6. It could be seen that MEL was well separated (from the interferent, ∗ in Figure 6), stacked, and detected in both tested milk samples using the established method within 20 min. For example, the blank YILI sample (without adding MEL, Figure 6-(A)) showed no MEL peak even under stacking mode, while a low concentration of 0.5 μmol/L MEL could be easily detected (Figure 6-(C)) under stacking mode, with a ~20 folds enhancement of sensitivity compared with traditional CZE mode (Figure 6-(B)); for the assay of WANGZAI reconstituted milk (with adding MEL at a final concentration of 8.0 μmol/L), similar phenomenon occurred (Figure 6-(D)). All these proved that this method was applicable for analyzing MEL in milk products.


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)

Electropherograms of real milk samples under optimized condition. (A)/(B)/(C) were samples from YILI pure milk; (D) was from WANGZAI reconstituted milk. Samples were treated with 60% acetonitrile (v/v) and were injected hydrodynamically at 50 mBar for 40 s. All samples also contained 8 mmol/L pH 2.8 phosphate solution and partial samples were added with MEL ((B)/(C) 0.5 μmol/L; (D) 8 μmol/L). Stacking was performed under +10.0 kV and results were detected at 200.0 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig6: Electropherograms of real milk samples under optimized condition. (A)/(B)/(C) were samples from YILI pure milk; (D) was from WANGZAI reconstituted milk. Samples were treated with 60% acetonitrile (v/v) and were injected hydrodynamically at 50 mBar for 40 s. All samples also contained 8 mmol/L pH 2.8 phosphate solution and partial samples were added with MEL ((B)/(C) 0.5 μmol/L; (D) 8 μmol/L). Stacking was performed under +10.0 kV and results were detected at 200.0 nm.
Mentions: The proposed method was applied to real milk samples. Separation and stacking results of two bands of milk products (YILI pure milk and WANGZAI reconstituted milk) were shown in Figure 6. It could be seen that MEL was well separated (from the interferent, ∗ in Figure 6), stacked, and detected in both tested milk samples using the established method within 20 min. For example, the blank YILI sample (without adding MEL, Figure 6-(A)) showed no MEL peak even under stacking mode, while a low concentration of 0.5 μmol/L MEL could be easily detected (Figure 6-(C)) under stacking mode, with a ~20 folds enhancement of sensitivity compared with traditional CZE mode (Figure 6-(B)); for the assay of WANGZAI reconstituted milk (with adding MEL at a final concentration of 8.0 μmol/L), similar phenomenon occurred (Figure 6-(D)). All these proved that this method was applicable for analyzing MEL in milk products.

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.


Related in: MedlinePlus