New Fully Portable Instrument for the Versatile Determination of Cations and Anions by Capillary Electrophoresis with Contactless Conductivity Detection

Abstract

A new portable capillary electrophoresis instrument with capacitively coupled contactless conductivity detection was developed and optimized for the sensitive field measurements of ionic compounds in environmental samples. It is powered by batteries and the high voltage modules are capable of delivering up to 15 kV at either polarity for more than one working day. Inorganic cations and anions, including ions of heavy metals and arsenate, could be determined with detection limits in the range from about 0.2 to 1 mM. The instrument was field tested in a remote region of Tasmania and nitrite and ammonium could be determined on-site at concentrations as low as 10 ppb in presence of other common inorganic ions at concentrations which were 2 to 3 orders of magnitude higher.

Identification of inorganic ions in post‐blast explosive residues using portable CE instrumentation and capacitively coupled contactless conductivity detection

“…C 4 D detection provided 10-fold lower detection limits and separations were completed more quickly compared with separations reported previously using the portable CE instrument with indirect photometric detection based on highly absorbing probes and LED light sources [11]. In comparison with other methods on portable CE instrumentation, the detection limits achieved for inorganic ions in this study were quite similar to those achieved by Kubáò et al [22] performing CE-C 4 D detection and those obtained by Kappes et al [33,34] using amperometric detection. Moreover, these detection limits are 1-3 orders of magnitude lower than those achieved using potentiometric or potential gradient detec- tion [32,33,35].…”

“…Of increasing interest is the use of portable and field-deployable instrumentation for these analyses so that the distance between sample collection and analysis can be minimised. CE is especially amenable to miniaturisation [21][22][23][24].…”

“…The first portable CE instrumentation was developed by Kappes and Hauser [32] and the instrument was equipped with potentiometric [32], amperometric [33] and conductometric [34] detectors, weighed 7.5 kg and was housed in a poly(vinyl chloride) case. More recently, Hauser and co-workers [22] designed a new portable instrument of similar dimensions, which was better suited to C 4 D detection, providing LODs as low as 10 mg/L for the separation of ten inorganic cations and five inorganic anions. The only other body of work utilising portable CE instrumentation is that of Li and co-workers.…”

Review on the development of truly portable andin-situcapillary electrophoresis systems

“…From the schematic given by Kubáň et al [86], the layout of the portable CE device was similar to that by Kappes et al [77], though the dimensions were slightly different: 310 mm × 220 mm × 260 mm. This meant that the volume was 1.7 times greater than that of the work by Kappes et al Further to this the control electronics to operate the portable CE system were housed in a separate aluminium box of dimensions 70 mm × 205 mm × 160 mm.…”

Quantification of plasma lactate concentrations using capillary electrophoresis with contactless conductivity detection

“…The CE instrument was purpose-built around a commercial high-voltage power supply module capable of delivering up to 30 kV (CZE 2000R, Spellman, Pulborough, UK) and otherwise similar to the design described in [42]. The detector was also built in-house.…”