A new CE with contactless conductivity detection method for the determination of complex cationic compositions: Application to the analysis of pen inks

Abstract

A CE with contactless conductivity detection methodology using a novel background electrolyte for the separation and determination of 17 metal cations (Cs , Rb , K , Ca , Na , Mg , Mn , Sr , Li , Ba , Fe , Pb , Cd , Zn , Co , Cu and Ni ) and ammonium has been investigated. The buffer, based on lactic acid and β-alanine, was experimentally compared with other two commonly used electrolytes, showing important improvements, such as shorter analysis times (<11 min), better electrophoretic resolutions and higher detectabilities for certain analytes, such as Fe and Pb . The inclusion of other additives such as 18-Crown-6 and α-hydroxyisobutyric acid was studied in order to obtain the best separation of the analytes of interest. The optimised method was applied to the analysis of 11 water-based pen inks and the determination of their metal composition. The methodology was demonstrated for the comparison and differentiation of pen inks.

A compact and high-performance setup of capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C4D)

“…There are several articles on the fundamental principles [5][6][7][8][9][10][11][12][13] of C 4 D and many reviews about the applications [14][15][16][17][18][19][20][21] of CE-C 4 D; Kubáň and Hauser have compiled a series of bi-yearly reviews on the developments of C 4 D dating back to 2009. [22][23][24][25][26][27][28][29] It has been proven that CE-C 4 D is a universal detection method for charged species and a powerful separation technique with high throughput, [30][31][32] short analysis time, [33][34][35] low sample consumption 19,36 and cost-effectiveness. 37-39 C 4 D is basically an electronic circuit, a feature that is beneficial for portable or miniature applications; the micro-CE-C 4 D is a more approachable alternative for routine water quality analysis and on-site analysis.…”

Capillary Electrophoresis: Trends and Recent Advances

“…Saiz et al utilized CE-C4D for the analysis of common cations and compared the performance of the conductivity detection-compatible BGEs (MES/HIS, Lac/His, and Lac/β-Ala) and emphasized that addition of 18-crown-6 and hydroxyisobutyric acid were essential for increasing the detection sensitivity. 61 CE-C4D was also used for the determination of bromate in water. 62 Utilizing electromembrane extraction as a sample pretreatment, LODs were in the subng/mL range.…”

“…Such analyses were predominantly performed using (indirect) UV–vis absorbance detection, , but C4D is increasingly applied. Saiz et al utilized CE-C4D for the analysis of common cations and compared the performance of the conductivity detection-compatible BGEs (MES/HIS, Lac/His, and Lac/β-Ala) and emphasized that addition of 18-crown-6 and hydroxyisobutyric acid were essential for increasing the detection sensitivity . CE-C4D was also used for the determination of bromate in water .…”

Contactless conductivity detection for analytical techniques: Developments from 2016 to 2018

“…Determination of major components during the hydrothermal treatment of biomass might be complicated due to the complex nature of the resulting liquid phase and a simple and robust CE‐C 4 D method was developed for determination of inorganic and organic anions therein . New BGE solutions for determination of inorganic cations, heavy metal cations, and ammonium were examined in order to achieve their efficient separation in pen inks . Inorganic anions/cations were determined in mineral fertilizers using dual‐channel CE‐C 4 D system with short capillaries and a semi‐automated set‐up for liquid delivery .…”