TY - JOUR

T1 - Imidazolium ionic liquids as dynamic and covalent modifiers of electrophoretic systems for determination of catecholamines

AU - Kolobova, Ekaterina

AU - Kartsova, Liudmila

AU - Kravchenko, Anastasia

AU - Bessonova, Elena

PY - 2018/10/1

Y1 - 2018/10/1

N2 - The subject of this study is comparison of imidazolium based dynamic and covalent coatings of the quartz capillary wall on the example of catecholamines determination. A way of synthesis of covalent coatings was proposed. For the first time different type of on-line sample preconcentration techniques (field-amplified sample stacking (FASS), head-column field amplified sample stacking (HC FASS), electrostacking, sweeping) were performed for catecholamines determination in N-alkylsubstituted imidazolium coated capillary. It was found that long chain imidazolium ionic liquids (C12MImCl and C16MImCl) in background electrolyte content create a dynamic coating of the quartz capillary walls and generate anode electroosmotic flow. Same is true for covalent coatings based on N-alkylsubstituted imidazolium. Both coatings prevent sorption of catecholamines on the internal surface of the quartz capillary. As a result efficiency and peak symmetry are increased. The maximum stacking efficiency factor (SEF) values for dynamic coatings were in range of 70–85, and limits of detection (LODs) were about 0.05 µg/ml under sweeping condition (micelle forming agent – C16MImCl) when the electric conductivity of sample matrix was higher than electric conductivity of BGE. In case of covalent coating, the maximum SEF values were higher than 1000, and LODs were about 1–2 ng/ml under sweeping condition (micelle forming agent – sodium dodecyl sulphate) in combination with electrostacking.

AB - The subject of this study is comparison of imidazolium based dynamic and covalent coatings of the quartz capillary wall on the example of catecholamines determination. A way of synthesis of covalent coatings was proposed. For the first time different type of on-line sample preconcentration techniques (field-amplified sample stacking (FASS), head-column field amplified sample stacking (HC FASS), electrostacking, sweeping) were performed for catecholamines determination in N-alkylsubstituted imidazolium coated capillary. It was found that long chain imidazolium ionic liquids (C12MImCl and C16MImCl) in background electrolyte content create a dynamic coating of the quartz capillary walls and generate anode electroosmotic flow. Same is true for covalent coatings based on N-alkylsubstituted imidazolium. Both coatings prevent sorption of catecholamines on the internal surface of the quartz capillary. As a result efficiency and peak symmetry are increased. The maximum stacking efficiency factor (SEF) values for dynamic coatings were in range of 70–85, and limits of detection (LODs) were about 0.05 µg/ml under sweeping condition (micelle forming agent – C16MImCl) when the electric conductivity of sample matrix was higher than electric conductivity of BGE. In case of covalent coating, the maximum SEF values were higher than 1000, and LODs were about 1–2 ng/ml under sweeping condition (micelle forming agent – sodium dodecyl sulphate) in combination with electrostacking.

KW - Capillary electrophoresis

KW - Catecholamines determination

KW - Dynamic and covalent coatings of the quartz capillary wall

KW - Imidazolium ionic liquids

UR - http://www.scopus.com/inward/record.url?scp=85047601541&partnerID=8YFLogxK

U2 - 10.1016/j.talanta.2018.05.057

DO - 10.1016/j.talanta.2018.05.057

M3 - Article

AN - SCOPUS:85047601541

VL - 188

SP - 183

EP - 191

JO - Talanta

JF - Talanta

SN - 0039-9140

IS - 183-191

ER -