Detection of Organic Pollutants in Soil by Laser-induced Fluorescence Spectroscopy

Soil organic pollutants have a wide range of sources, high harm and limited monitoring means, which is another environmental problem that has attracted global attention after water pollution and air pollution. Rapid on-line detection and analysis of soil organic pollution is of great significance for agricultural production, soil investigation and soil remediation. Laser induced fluorescence (LIF) spectroscopy is a kind of photoluminescence based material composition and content analysis technology, which has the characteristics of low sample usage, simple pretreatment process, fast detection speed and so on. It is widely used in many fields, such as environmental science, biological analysis, life science and so on.

Detecting Oil Pollutants in Soil

Oil pollution in the soil mainly comes from oil pollution emissions and leakage during the extraction, refining, storage, and transportation of petroleum hydrocarbon products, sedimentation of atmospheric pollutants generated by the combustion of petroleum hydrocarbons, and the use of various pesticides, preservatives, herbicide solvents or emulsifiers. Oils have high viscosity and poor hydrophilicity. After entering the environmental soil, they will damage the soil water-air balance, reduce soil activity, affect plant growth and microbial population structure, and are more likely to penetrate into shallow groundwater, causing water pollution and diffusion. Petroleum hydrocarbons in soil cause air pollution through volatilization, diffusion and transfer. In addition, pollutants can enter the human body through respiration, crop enrichment and other behaviors, causing harm to the human body. The harm caused by oil-contaminated soil has attracted widespread attention, and monitoring the pollution status of oil-based soil is of great significance. The common analytical methods of petroleum organic pollutants are chromatography and gravimetric method, including high performance liquid chromatography, gas chromatography, dichloromethane extraction gravimetric method and so on. These methods need to use different organic solvents to extract oil organic matter from soil. Sample pretreatment is relatively complex. In recent years, LIF technology has been applied to the direct detection of oil pollutants in soil because of its simple operation and high detection efficiency. Different oils have different components and molecular structures, and show their own fluorescence spectra under laser excitation. LIF can be used to identify the composition of different oily soils.

Detection of Polycyclic Aromatic Hydrocarbons in Soil

Polycyclic aromatic hydrocarbons (PAHs) are hydrocarbons containing two or more benzene rings in the molecule. It originates from incomplete combustion of petroleum, tobacco, wood, coal, organic polymer compounds, and landfills. These pollutants enter the soil system through atmospheric sedimentation, sewage irrigation, etc., which pose a potential threat to soil-based flora and fauna, human production and life. PAHs have stable physical and chemical properties, chronic toxicity, carcinogenesis, teratogenicity, mutagenicity and other hazards. They are easy to be enriched in organisms and cause harm to human health through the food chain. It is one of the most important environmental pollutants in the world. The rapid and on-site monitoring of PAHs in soil is of great significance. The application of LIF technology to the monitoring of PAHs in soil has become the research focus of scholars. In order to verify the feasibility of direct detection of PAHs in soil by LIF technology, the researchers prepared corresponding PAHs soil samples through the laboratory, and established a quantitative relationship between PAHs concentration and fluorescence intensity. The research showed that within a certain concentration range, there is a significant linear relationship between the concentration of PAHs and its fluorescence intensity, and LIF technology can be applied to the direct detection of PAHs in soil.

Detection of Pesticides in Soil

The accelerated process of agricultural modernization has led to a substantial increase in the use of pesticides. When pesticides, fungicides and herbicides applied to soil and vegetation exceed the self-purification capacity of environmental soil, It will cause destructive damage to the microorganisms, animals and plants in the soil, which can improve the soil structure and function, so as to reduce the soil activity. Pesticides are absorbed and enriched by crops, accumulated in the human body through the food chain, causing harm to the human body; through environmental migration, ecosystem cycle causes pollution to water resources and atmosphere. The monitoring of soil pesticide pollution is one of the important references to measure the degree of soil pollution. Common methods for the detection and analysis of organophosphorus and organochlorine pesticides include chromatography (gas chromatography and liquid chromatography) and gas chromatography-mass spectrometry, but the above methods require a large amount of reagents and expensive equipment. LIF technology is simple and convenient to operate, which can realize the rapid detection and identification of pesticide pollutants and pesticide residues.

Alfa Chemistry Testing Lab is the world's leading third-party testing company, which can provide one-stop analysis and testing solutions for soil.

Related Services