Nadia Mira Kusumaningtyas a b, Sukumaporn Saengsuk a, Apinya Obma a, Supa Wirasate c, Peter C. Hauser d, Rattikan Chantiwas a
a Department of Chemistry and Center
of Excellence for Innovation in Chemistry, Faculty of Science, Mahidol
University, Rama VI Rd., Bangkok, 10400, Thailand
b Department of Pharmacy, Faculty of
Health Science, Universitas Darussalam Gontor, Jl. Raya Siman, Ponorogo, 63471,
Indonesia
c Rubber Technology Research Centre
and Center for Surface Science and Engineering, Faculty of Science, Mahidol
University, Salaya, Nakhon Pathom, 73170, Thailand
d The University of Basel, Department
of Chemistry, Klingelbergstrasse 80, CH-4056, Basel, Switzerland
* Corresponding author. E-mail addresses:
rattikan.cha@mahidol.ac.th, rattikan.cha@mahidol.edu(R. Chantiwas).
Abstract:
Background
This study introduces a
polyallylamine (PAA)-coated capillary electrophoresis (CE) method combined with
capacitively coupled contactless conductivity detection (C4D) for
the rapid and efficient separation of anions in bread. This approach utilizes
suppressed cathodic electroosmotic flow (EOF) for improved separation
performance. In contrast to conventional reversed – EOF methods that depend on
dynamic cetyltrimethylammonium bromide (CTAB) coatings, which require long
equilibration times and result in peak drift, this work utilizes a stable,
covalently grafted PAA coating achieved through
3-glycidoxypropyltrimethoxysilane. This stable coating effectively regulates
cathodic EOF, producing more reliable and reproducible separation results.
Results
Polyallylamine-coated
capillary surface achieves a stable and significantly reduced cathodic
electroosmotic flow (EOF), improving separation efficiency. The plate number (N)
0.4 × 105 – 0.9 × 105 m−1,
while resolution is enhanced, enabling the quantification of 20 anions within a
shortened separation time (∼10 min), thereby
improving the overall performance of the method. This method also demonstrated
excellent reproducibility, with %RSD of relative migration time
(RMT) < 0.5 %. This is a notable advancement over
conventional reversed EOF methods, which typically experience higher variation.
The system’s EOF mobility, efficiency (plate number and resolution), precision,
and long-term surface stability with over 80 consecutive runs were thoroughly
validated. Thereby confirms the robustness and repeatability of the technique
for applications, particularly in complex matrices such as bread analysis.
Significance
This coating approach
enables stable and reproducible CE-C4D analysis of anions with a
capillary coated with 0.01 % PAA reagent. The covalently bonded PAA
suppresses cathodic EOF, eliminates buffer additives, and ensures consistent
migration times over 80 separation cycles. Compared with conventional CTAB
coatings, the PAA-coated capillary offers higher stability, improved
sensitivity with larger peak areas, and enhanced reproducibility, enabling
identification of 20 anions in bread samples within ∼10 min for
high-throughput food analysis.
KEYWORDS
Polyallylamine coated capillary; Suppressed cathodic EOF; Anion separation; Surface coating; CE-C4D
Reference:
Kusumaningtyas, N. M.; Saengsuk, S.; Obma, A.; Wirasate, S.; Hauser, P. C.; Chantiwas, R. Polyallylamine-coated capillary electrophoresis with capacitively coupled contactless conductivity detection for rapid analysis of functional anions in bread. Analytica Chimica Acta 2026, 1382, 344833. doi: 10.1016/j.aca.2025.344833
