Precise estimation of sodium dodecylbenzenesulfonate (DBS) is essential for understanding its adsorption in soils, transport, toxicity, fate, and its application in the remediation of contaminated soil and groundwater. DBS can be easily identified by its conjugated double bond systems of benzene rings under the ultraviolet (UV) spectrum of a spectrophotometer. However, benzene group components of dissolved organic matter (DOM) also absorb light in the UV spectrum, and this effect is responsible for the excess quantities of DBS that are falsely measured by spectrophotometers. This study was conducted to propose a method for accurately measuring the DBS concentration of a solution containing DOM. To elucidate the influence of DOM during the UV-spectroscopic measurement of DBS in an aqueous solution, 222.5 nm UV and 400 nm UV–vis spectra were measured. The DOM was extracted from a highly humic non-allophanic volcanic ash (Andosol) soil by using 1 mmol NaCl/L and 100 mmol NaCl/L solutions as the extractants. The absorbances at both 222.5 and 400 nm increased in proportion to the increase in the DOM concentration. The relationship between the absorbances at the two different wavelengths could be expressed as a linear relationship. On the other hand, the absorbance at 400 nm did not increase with the increase in the DBS concentration, whereas the absorbance at 222.5 nm increased with the increase in the DOM concentration. Therefore, we inferred that the influence of DOM on the absorbance value of the DBS–DOM complex solution at 222.5 nm could be eliminated by using the linear relationship between the two different absorbances of the DBS-free DOM solution. This method makes it possible to easily measure the DBS concentration of a solution from soil water, streams or industrial effluents containing DOM, without using reagents.

中文翻译：

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紫外分光光度法精确估算含有从土壤中提取的溶解性有机物的水溶液中的十二烷基苯磺酸盐

十二烷基苯磺酸钠 (DBS) 的精确估算对于了解其在土壤中的吸附、迁移、毒性、归宿及其在污染土壤和地下水修复中的应用至关重要。在分光光度计的紫外 (UV) 光谱下，DBS 可以通过苯环的共轭双键系统轻松识别。然而，溶解有机物 (DOM) 的苯组成分也会吸收紫外光谱中的光，这种效应是导致分光光度计错误测量 DBS 的原因。本研究旨在提出一种准确测量含有 DOM 的溶液中 DBS 浓度的方法。为了阐明 DOM 在水溶液中 DBS 的紫外光谱测量过程中的影响，222。测量了 5 nm 紫外和 400 nm 紫外-可见光谱。使用 1 mmol NaCl/L 和 100 mmol NaCl/L 溶液作为萃取剂，从高腐殖质非尿素火山灰 (Andosol) 土壤中提取 DOM。222.5 和 400 nm 处的吸光度随着 DOM 浓度的增加而增加。两个不同波长处的吸光度之间的关系可以表示为线性关系。另一方面，400 nm 处的吸光度没有随着 DBS 浓度的增加而增加，而 222.5 nm 处的吸光度随着 DOM 浓度的增加而增加。因此，我们推断 DOM 对 DBS-DOM 复合溶液在 222 处吸光度值的影响。通过使用无 DBS DOM 溶液的两种不同吸光度之间的线性关系，可以消除 5 nm。这种方法可以轻松测量土壤水、溪流或含有 DOM 的工业废水中溶液的 DBS 浓度，而无需使用试剂。