A novel hybrid mode of sample injection to enhance CZE sensitivity for simultaneous determination of a pyridine‐triphenylborane anti‐fouling agent and its degradation products

Abstract

We developed a novel hybrid sample injection mode (HSIM) that presents the combination of electrokinetic injection and vacuum injection to enhance detection sensitivity in CZE. Samples were introduced using both vacuum and electrokinetic injections simultaneously, with a water plug injected into the capillary prior to sample introduction (i.e. similarly to field-amplified sample injection, FASI). Using a sample mixture containing an anti-fouling agent applied to ship hulls, pyridine-triphenylborane and its degradation products (diphenylborinic acid, phenylboronic acid, and phenol) dissolved in ACN, the length of water plug, time, and voltage for sample introduction were optimized. The signal intensity (peak height) was found to be up to a 30-fold increased using HSIM by applying 4 kV for 4 s at the inlet end of the capillary as the cathode with supplementary vacuum in comparison with only vacuum injection for 4 s. The LODs (at a S/N of 3) for pyridine-triphenylborane, diphenylborinic acid, phenylboronic acid, and phenol were 0.88, 1.0, 21, and 23 μg/L, respectively. At the level of 0.04 mg/L, the RSDs (n=4, intra-day) for the above analytes were in the ranges of 1.9-11, 4.3-9.2, and 0.34-0.66% for peak area, peak height, and migration time, respectively. The HSIM is a simple and promising procedure useful for enhancing the sensitivity for both low-and high-mobility ions in CZE.

Simultaneous Determination of Pyridine-Triphenylborane Anti-Fouling Agent and Its Degradation Products in Paint-Waste Samples Using Capillary Zone Electrophoresis with Field-Amplified Sample Injection

“…The RSDs of the peak area for PTPB, DPB, MPB, and phenol were obtained as 6.2 -14%, for peak heights of 5.9 -10%, and for migration times of 0.49 -0.62%. The LODs obtained using the FASI-CZE were similar to those obtained using the HSIM-CZE; 35 the LODs of PTPB and DPB were ca. 30 times lower than those for the vacuum injection procedure, but the LODs of MPB and phenol were similar to those for the vacuum injection procedure.…”

“…The same BGE, adjusted to pH 9.8, as used in our previous study, 35 was adopted here so that the all analytes would exist as anions in the alkaline BGE. The sample inlet side must be set as the cathode to inject the analytes into the capillary using FASI.…”

“…33 Consequently, no analytical method is available for the simultaneous determination of PTPB, DPB, MPB, and phenol, except for our previous methods. 34,35 We previously developed a capillary zone electrophoresis (CZE) with direct UV detection for the simultaneous determination of PTPB, DPB, MPB, and phenol. 34 Furthermore, a novel hybrid sample injection mode (HSIM) that presents the combination of FASI and vacuum injection was proposed to enhance the detection sensitivity.…”

“…34 Furthermore, a novel hybrid sample injection mode (HSIM) that presents the combination of FASI and vacuum injection was proposed to enhance the detection sensitivity. 35 In fact, HSIM cannot be used for some commercial instruments: EKI and vacuum injection modes are inapplicable simultaneously. Moreover, when the HSIM is applied to the analysis of real samples, such as paint wastes, its separation efficiency might be degraded because of coexisting substances in the samples and the sample solvent introduced simultaneously.…”

Degradation of triphenylborane–pyridine antifouling agent in water by copper ions

“…[6] It was impossible for us to quantify TPBP, DPB, and MPB simultaneously using the HPLC system proposed by the ISO. [11] A hydrolysis and photolysis study of TPBP in water has been reported, [7] and an ecotoxicity study examining microalgae and crustaceans indicates the high toxicity of TPBP and much lower toxicity of the other phenylborane derivatives and some known degradation products. [11] A hydrolysis and photolysis study of TPBP in water has been reported, [7] and an ecotoxicity study examining microalgae and crustaceans indicates the high toxicity of TPBP and much lower toxicity of the other phenylborane derivatives and some known degradation products.…”