Analysis of α, β, γ-hexachlorocyclohexanes in water by novel activated carbon fiber-solid phase microextraction coupled with gas chromatography—mass spectrometry

A fast and simple method for determination of α, β, γ-hexachlorocyclohexanes (HCHs) in water using activated carbon fiber-solid phase microextraction(ACF-SPME) were studied. Results showed the performance of adsorption and desorption of three HCHs on ACF were excellent. A wide linear range from 10 to 100 μg/L and detection limits of the ng/L level were obtained using ACF-SPME with GC-MS in selected ion monitoring(SIM) acquisition mode. The proposed method was also successfully applied for determination of three HCHs in tap water. Compared to commercial fibers, ACF showed some advantages such as better resistance to solvents, higher thermal stability, longer lifetime and lower cost. The data demonstrated that GC-MS with ACF-SPME is well suitable for the analysis of HCHs in water.

Modeling historical budget for β-Hexachlorocyclohexane(HCH)in the Arctic Ocean:A contrast to α-HCH

The historical annual loading to,removal from,and cumulative burden in the Arctic Ocean for β-hexachlorocyclohexane(β-HCH),an isomer comprising 5e12%of technical HCH,is investigated using a mass balance box model from 1945 to 2020.Over the 76 years,loading occurred predominantly through ocean currents and river inflow(83%)and only a small portion via atmospheric transport(16%).β-HCH started to accumulate in the Arctic Ocean in the late 1940s,reached a peak of 810 t in 1986,and decreased to 87 t in 2020,when its concentrations in the Arctic water and air were~30 ng m^(-3)and~0.02 pg m^(-3),respectively.Even though β-HCH and α-HCH(60e70%of technical HCH)are both the isomers of HCHs with almost identical temporal and spatial emission patterns,these two chemicals have shown different major pathways entering the Arctic.Different from α-HCH with the long-range atmospheric transport(LRAT)as its major transport pathway,β-HCH reached the Arctic mainly through long-range oceanic transport(LROT).The much higher tendency of β-HCH to partition into the water,mainly due to its much lower Henry's Law Constant than α-HCH,produced an exceptionally strong pathway divergence with β-HCH favoring slow transport in water and α-HCH favoring rapid transport in air.The concentration and burden of β-HCH in the Arctic Ocean are also predicted for the year 2050 when only 4.4-5.3 t will remain in the Arctic Ocean under the influence of climate change.