Rapid determination method for hydrophobic organic matter LDPE membrane/water distribution coefficient based on enhanced extraction of surfactant

Abstract

The invention relates to a rapid determination method for a hydrophobic organic matter LDPE membrane / water distribution coefficient based on enhanced extraction of a surfactant. According to the rapiddetermination method, the surfactant is utilizes as an indirect method medium, and the method for precisely and quick determining the hydrophobic organic matter LDPE membrane / water distribution coefficient is established by determining a distribution coefficient of hydrophobic organic matter in a micelle and a distribution coefficient of the hydrophobic organic matter in the micelle and LDPE. According to the rapid determination method, direct determining of the hydrophobic organic matter in an aqueous phase is avoided, meanwhile, the time for reaching extraction balance of a target object inthe LDPE and a micelle phase is shortened, the purpose of quick and precise determining can be achieved, and the experimental and theoretical basis is provided for field site determination. The ideaof introducing the indirect method medium is fused into the specific problem of the membrane / water distribution coefficient, and the theoretical basis and technical support are provided for further expanding of the application range of a passive sampling technology adopting the LDPE as an adsorption phase and developing of a novel passive sampling technology process.

Description

technical field [0001] The invention relates to the technical field of LDPE passive sampling, in particular to a method for quickly determining the partition coefficient of hydrophobic organic matter LDPE film / water based on surfactant-enhanced extraction. Background technique [0002] Hydrophobic Organic Contaminants (HOC S ) is carcinogenic, teratogenic and mutagenic, and is more harmful to organisms. As an emerging passive sampling technology, LDPE (low-density polyethylene film) is gradually applied to HOC in water bodies S concentration monitoring. So how to measure HOC S Partition coefficient between LDPE and aqueous phase K PE-w appears to be particularly important. Determination by LDPE technique K PE-w There are mainly direct method and indirect method, for the strong hydrophobic organic pollutants, the direct method takes too long to measure, and the accuracy is difficult to guarantee, which brings many difficulties to sampling and measurement, while the ind...

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Problems solved by technology

Determination by LDPE technique K PE-w There are mainly direct method and indirect method, for the strong hydrophobic organic pollutants, the direct method takes too long to measure, and the accuracy is difficult to guarantee, which brings many difficulties to sampling and measurement, while the indirect method has less research, only It was found that based on the methanol-water mixture system K PE-w Determination of value, due to factors of methanol itself also lead to inaccurate determination results

At the same time, factors such as absorption on the wall surface, volatile loss, and partial precipitation caused by the low solubility of the analyte will also cause large errors.

[0003] Before the present invention, directly put LDPE into pollutant aqueous solution, regularly monitor LDPE adsorption concentration, can measure K PE-w value, but there are defects that last from tens to hundreds of days, especially for strongly hydrophobic organic substances, their solubility is very low, which brings great uncertainty to the measurement results; through indirect methods Adding methanol solution to the system can indeed shorten the time to achieve extraction equilibrium to a certain extent, but because methanol solution can also pass through the LDPE membrane freely, some methanol solution will remain inside the membrane, resulting in high or inaccurate results

At the same time, regarding strongly hydrophobic organic compounds K PE-w Determination of value, log K PE-w with log K ow Whether there is a linear relationship between, HOC S There are also few reports on the adsorption process and influencing factors of LDPE membranes, especially for the application and promotion of the indirect method for determining the LDPE membrane / water partition coefficient and its determination methods, so far no reports have been reported.

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