Amperometric Determination of Aminobiphenyls Using HPLC‐ED with Boron‐Doped Diamond Electrode

Abstract

Amino derivatives of biphenyl have been proven to be genotoxic and/or carcinogenic, thus they are widely monitored in the environment as well as in biological liquids. This study was devoted to HPLC determination of 2-aminobiphenyl, 3-aminobiphenyl, and 4-aminobiphenyl in model drinking and river water samples using amperometric detection in a thin layer cell with boron doped diamond thin film electrode. Satisfactory separation of studied analytes was achieved at a ChiraDex column (Merck, Germany) with chemically bonded b-cyclodextrin in a mobile phase aqueous buffer/acetonitrile/methanol (40/30/30, v/v/v) with total separation time of six minutes. The highest detector response with satisfactory repeatability (relative standard deviation < 2.9% for all aminobiphenyls) was obtained using 0.01 mol L À1 acetate buffer at pH 5.0 as an aqueous component of the mobile phase. For direct determination of aminobiphenyls in drinking and river water model samples limits of quantitation ca. 4 Â 10 À7 mol L À1were achieved. Applying off-line solid phase extraction using Lichrolut EN (Merck, Germany) cartridges and elution by diethyl ether, limits of quantitation were lowered down to the 10 À9 mol L À1 concentration range.

Thin‐Layer and Wall‐Jet Arrangement of Amperometric Detector with Boron‐Doped Diamond Electrode: Comparison of Amperometric Determination of Aminobiphenyls in HPLC‐ED

“…The presented study is a continuation of those voltammetric [18] and amperometric studies [20,21] devoted exclusively to 2-AB, 3-AB, and 4-AB. In the former study we characterized the voltammetric behavior of these analytes by cyclic voltammetry at nanocrystalline BDD electrode and reported repeatable results with limits of quantitation (LOQs) in the 10 À7 mol L À1 concentration range for their differential pulse voltammetric (DPV) determination.…”

“…The position of the amino group influences the overall shape of the amino derivative and thus the strength of its interaction with b-cyclodextrin. Therefore, the retention mechanism is rather different from that using reversed phase and it is pH-independent [20].…”

“…In the former study we characterized the voltammetric behavior of these analytes by cyclic voltammetry at nanocrystalline BDD electrode and reported repeatable results with limits of quantitation (LOQs) in the 10 À7 mol L À1 concentration range for their differential pulse voltammetric (DPV) determination. The latter studies [20,21] focused on the amperometric detection of these ABs in HPLC using microcrystalline BDD electrode in thin-layer cell. Their baseline separation was achieved at a ChiraDex column (Merck, Germany) with chemically bonded b-cyclodextrin in a mobile phase 0.01 mol L À1 acetate buffer pH 5.0/acetonitrile/methanol (40/30/30, v/v/v) within 6 min characterized by capacity factors of 0.36, 0.81, and 1.28, for 2-AB, 3-AB, and 4-AB, respectively.…”

“…GC including GC-MS is most frequently used despite the necessity to derivatize the amines to overcome their polar character [25,27,[30][31][32][33][34][35]. The derivatization step is not necessary for HPLC, which can be (beside the universal spectrophotometric detection [30,36]) coupled to the more selective fluorescence, MS [27] or electrochemical detection [20,21,[37][38][39][40]. Recently, several rapid methods based on capillary electrophoresis [41,42] or m-HPLC [43] have been described.…”

“…In our laboratory, a pen-type BDD disk electrode was designed [2] and successfully used for voltammetric determination of 2-aminobiphenyl (2-AB), 3-aminobiphenyl (3-AB), and 4-aminobiphenyl (4-AB) [18], 3-nitrofluoranthene and 3-aminofluoranthene [19], and phenolic compounds in foods [13]; in the latter study this electrode was also employed in laboratory-made wall-jet amperometric detection cell. The thin-layer arrangement was tested for HPLC-ED determination of aminobiphenyls (ABs) [20,21], widespread environmental pollutants [22] with potential (2-AB and 3-AB) or proven (4-AB) carcinogenic effect to humans [23]. These compounds are used as raw material or intermediates in manufacturing of pesticides, dyestuffs, polymers and other industrial chemicals [24] and enter the environment due to their relatively high polarity and water solubility.…”