Electromembrane extraction and capillary electrophoresis with capacitively coupled contactless conductivity detection: Multi‐extraction capabilities to analyses trace metals from saline samples. Issue 16 (13th June 2018)

• Record Type: Journal Article
• Authors: Silva, Macarena; Mendiguchía, Carolina; Moreno, Carlos; Kubáň, Pavel
• Is Part Of: Electrophoresis. Volume 39:Issue 16(2018)
• Page Start: 2152
• Page End: 2159
• Publication Date: 2018-06-13
• Subjects: CE -- DEHPA -- Electromembrane extraction -- Major inorganic cations -- Metal cations -- Saline samples; Electrophoresis -- Periodicals; Electrophoresis -- Periodicals; 541.372
• DOI: 10.1002/elps.201800125
• Languages: English
• ISSNs: 0173-0835

Abstract

Abstract: Simultaneous electromembrane extraction (EME) of six trace metal cations (Cu 2+, Zn 2+, Co 2+, Ni 2+, Pb 2+, Cd 2+ ) from saline samples was investigated. CE with capacitively coupled contactless conductivity detection (C 4 D) was used to determine the metals in acceptor solutions due to its excellent compatibility with the minute volumes of acceptor solutions. Bis(2‐ethylhexyl)phosphate (DEHPA) was selected as a suitable nonselective modifier for EME transport of target metal cations. Both, the individual effect of each major inorganic cation (Na +, K +, Ca 2+, Mg 2+ ) and their synergistic effect on EME of the trace metal cations were evaluated. In both cases, a decrease in extraction efficiency was observed when major inorganic cations were present in the sample. This effect was more significant for Ca 2+ and Mg 2+ . The system was optimized for simultaneous extractions of the six target metals from saline samples (50 mM Na +, 5 mM Mg 2+, 1 mM K +, and 1 mM Ca 2+ ) and following EME conditions were applied. Organic phase consisted of 1‐nonanol containing 1% (v/v) DEHPA, acceptor solution was 1 M acetic acid (HAc) and sample pH was adjusted to 5. Sample was stirred at 750 rpm and EMEs were carried out at extraction potential of 10 V for 20 min. The method presented a repeatability between 8 and 21.8% ( n = 5), good linearity in 0.5–10 μM concentration range ( R 2 = 0.987‐0.999) and LOD better than 2.6 nM. Applicability of the EME–CE–C 4 D method to the analyses of metal cations in drinking water, seawater, and urine samples was also demonstrated.