Abstract
In sample-stacking techniques, the detection limit cannot be improved by simply increasing the length of the sample solution, because the individual electrophoretic parameters must be optimized. In an attempt to increase the amount of sample injected, as well as to focus them onto a small zone, two novel methods are proposed. One of these employs an "ultra-high conductivity zone", which was inserted between the sample zone and background solution to build an unequal conductivity gradient. The other employs a "low temperature bath". A portion of the capillary (near the junction between the sample solution and the background solution) was immersed in a low temperature bath, which served as a "pseudo-high-conductivity zone" due to the fact that conductivity would increases when the temperature is decreased. As a result, a large volume of sample injection can be achieved. Using 3,4-methylenedioxymethamphetamine as a model compound, the detection limit was determined to be 1.6 × 10-6 M (S/N = 3) by means of normal non-aqueous capillary electrophoresis (NACE). This could be improved to 3.0 × 10-8 M, 4.8 × 10-9 M and 5.0 × 10 -9 M, respectively, when the normal stacking, ultra-high conductivity zone NACE-stacking and the low-temperature zone NACE-stacking methods were applied.
| Original language | English |
|---|---|
| Pages (from-to) | 115-121 |
| Number of pages | 7 |
| Journal | Journal of Chromatography A |
| Volume | 1068 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2005 Mar 11 |
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Keywords
- 3,4- Methylenedioxymethamphetamine
- Non-aqueous capillary electrophoresis
- Stacking
ASJC Scopus subject areas
- Analytical Chemistry
- Biochemistry
- Organic Chemistry
Cite this
Sample-stacking techniques in non-aqueous capillary electrophoresis. / Tsai, Chih Hsin; Tsai, Chung Chen; Liu, Ju Tsung; Lin, Cheng-Huang.
In: Journal of Chromatography A, Vol. 1068, No. 1, 11.03.2005, p. 115-121.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Sample-stacking techniques in non-aqueous capillary electrophoresis
AU - Tsai, Chih Hsin
AU - Tsai, Chung Chen
AU - Liu, Ju Tsung
AU - Lin, Cheng-Huang
PY - 2005/3/11
Y1 - 2005/3/11
N2 - In sample-stacking techniques, the detection limit cannot be improved by simply increasing the length of the sample solution, because the individual electrophoretic parameters must be optimized. In an attempt to increase the amount of sample injected, as well as to focus them onto a small zone, two novel methods are proposed. One of these employs an "ultra-high conductivity zone", which was inserted between the sample zone and background solution to build an unequal conductivity gradient. The other employs a "low temperature bath". A portion of the capillary (near the junction between the sample solution and the background solution) was immersed in a low temperature bath, which served as a "pseudo-high-conductivity zone" due to the fact that conductivity would increases when the temperature is decreased. As a result, a large volume of sample injection can be achieved. Using 3,4-methylenedioxymethamphetamine as a model compound, the detection limit was determined to be 1.6 × 10-6 M (S/N = 3) by means of normal non-aqueous capillary electrophoresis (NACE). This could be improved to 3.0 × 10-8 M, 4.8 × 10-9 M and 5.0 × 10 -9 M, respectively, when the normal stacking, ultra-high conductivity zone NACE-stacking and the low-temperature zone NACE-stacking methods were applied.
AB - In sample-stacking techniques, the detection limit cannot be improved by simply increasing the length of the sample solution, because the individual electrophoretic parameters must be optimized. In an attempt to increase the amount of sample injected, as well as to focus them onto a small zone, two novel methods are proposed. One of these employs an "ultra-high conductivity zone", which was inserted between the sample zone and background solution to build an unequal conductivity gradient. The other employs a "low temperature bath". A portion of the capillary (near the junction between the sample solution and the background solution) was immersed in a low temperature bath, which served as a "pseudo-high-conductivity zone" due to the fact that conductivity would increases when the temperature is decreased. As a result, a large volume of sample injection can be achieved. Using 3,4-methylenedioxymethamphetamine as a model compound, the detection limit was determined to be 1.6 × 10-6 M (S/N = 3) by means of normal non-aqueous capillary electrophoresis (NACE). This could be improved to 3.0 × 10-8 M, 4.8 × 10-9 M and 5.0 × 10 -9 M, respectively, when the normal stacking, ultra-high conductivity zone NACE-stacking and the low-temperature zone NACE-stacking methods were applied.
KW - 3,4- Methylenedioxymethamphetamine
KW - Non-aqueous capillary electrophoresis
KW - Stacking
UR - http://www.scopus.com/inward/record.url?scp=17644422211&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=17644422211&partnerID=8YFLogxK
U2 - 10.1016/j.chroma.2004.12.095
DO - 10.1016/j.chroma.2004.12.095
M3 - Article
C2 - 15844549
AN - SCOPUS:17644422211
VL - 1068
SP - 115
EP - 121
JO - Journal of Chromatography
JF - Journal of Chromatography
SN - 0021-9673
IS - 1
ER -