Determination of polyhalogenated carbazoles in waters at low nanogram‐per‐liter concentrations with solid‐phase disk extraction

Abstract

Polyhalogenated carbazoles, a class of emerging contaminants with persistence and dioxin-like toxicity, have received increasing attention in recent years. In this study, a simple, rapid, sensitive, and high throughput method based on solidphase disk extraction and gas chromatography-mass spectrometry was described for the determination of polyhalogenated carbazoles in low nanogram-per-liter range in water samples. The proposed solid-phase disk extraction method was initially optimized, and the optimum experimental conditions found were 1 L water sample (pH 6-9) extracted and enriched by Empore 3-stn octadecyl disk at flow rate of 5 to 50 mL/min and eluted by 5 mL of acetone and 3 × 10 mL methylene dichloride. The linearity of the method ranged from 0.2 to 50 ng/L for carbazole and 11 polyhalogenated carbazoles, with correlation coefficients ranging from 0.9951 to 0.9996. The limits of detection were in the low nanogram per liter level, ranging from 0.018 to 0.12 ng/L. Finally, the optimized method was applied for determining trace levels of carbazole and 11 polyhalogenated carbazoles in tap water and seawater samples with good recovery of 86.6-112.8%. Carbazole and 3-7 polyhalogenated carbazoles were detected, and 3,6-dichlorocarbazole was the predominant congener both in tap water and seawater.

Production of Polyhalogenated Carbazoles in Marine Red Alga Corallina officinalis: A Possible Natural Source

“…More than 20 PHCZs have been subsequently identified in sediment, soil, air, water, and biota samples since the first identification of 1368-CCZ in the sediment of Buffalo River, New York. − In recent years, PHCZs have been increasingly measured in the marine environment. Studies showed that the most frequently detected PHCZs were 36-CCZ, 3-CCZ, and 36-BCZ in seawater from several regions of China. − The most abundant PHCZs in the surface sediment from the Yangtze River estuary and the adjacent East China Sea were 36-CCZ, 3-CCZ, and 36-BCZ, with mean concentrations of 0.62, 0.15, and 0.14 ng/g, respectively . In contrast, the dominant PHCZs in the surface sediment from the northern South China Sea followed the order 36-CCZ (0.03–0.93 ng/g), 36-BCZ (0–1.14 ng/g), and 1368-BCZ (<0.007–0.37 ng/g) .…”

Calixarenes and cyclodextrins as off- and on-fluorescence probes for carbazole

“…Some others report better LOD by SPE-RTP with a laborious procedure(0.015) [36], or with SPE-GC-MS, depending on the type of SPE (10 32 and 1 31 ). Also, much lower LOD have been published, for example, based on solid phase disk extraction-GC-MS (0.001) [52], or by a tandem method by UPLC/MS/MS (0.003) [53].…”