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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 sample with/without the NaOH flushing step. (A) The first run of real sample with NaOH rinsing step; (B) the second run without NaOH rinsing step; and (C) the third run with NaOH re-rinsing. Condition: see Figure 3.
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fig5: Electropherograms of real sample with/without the NaOH flushing step. (A) The first run of real sample with NaOH rinsing step; (B) the second run without NaOH rinsing step; and (C) the third run with NaOH re-rinsing. Condition: see Figure 3.

Mentions: As the status of the inner-wall silanol greatly affected reproducibility of the method, special rinsing step was added before each run. It could be seen in Figure 5 that an additional 0.1 mmol/L NaOH rinsing step was crucial for maintaining reproducibility. Without NaOH rinsing step (capillary was only flushed with water and running buffer for 1.0 min and 3.0 min respectively, Figure 5-(B)), the separation and stacking were ruined compared with the first run (Figure 5-(A)). When the NaOH rinsing step was added before the next assay, better separation and stacking regained (Figure 5-(C)). For the selection of the NaOH rinsing time, our data proved that the 0.1 mmol/L NaOH rinsing time should be at least 3.0 min in order to achieve satisfied reproducibility.


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 sample with/without the NaOH flushing step. (A) The first run of real sample with NaOH rinsing step; (B) the second run without NaOH rinsing step; and (C) the third run with NaOH re-rinsing. Condition: see Figure 3.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig5: Electropherograms of real sample with/without the NaOH flushing step. (A) The first run of real sample with NaOH rinsing step; (B) the second run without NaOH rinsing step; and (C) the third run with NaOH re-rinsing. Condition: see Figure 3.
Mentions: As the status of the inner-wall silanol greatly affected reproducibility of the method, special rinsing step was added before each run. It could be seen in Figure 5 that an additional 0.1 mmol/L NaOH rinsing step was crucial for maintaining reproducibility. Without NaOH rinsing step (capillary was only flushed with water and running buffer for 1.0 min and 3.0 min respectively, Figure 5-(B)), the separation and stacking were ruined compared with the first run (Figure 5-(A)). When the NaOH rinsing step was added before the next assay, better separation and stacking regained (Figure 5-(C)). For the selection of the NaOH rinsing time, our data proved that the 0.1 mmol/L NaOH rinsing time should be at least 3.0 min in order to achieve satisfied reproducibility.

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