Semivolatile Petroleum Products Testing

According to the classification principle of indoor organic matter by the world health organization (WHO), semi-volatile organic compounds (SVOC) refers to the organic matter with boiling points between 240 ~ 400 °C and the vapor pressure is between at (0.1 ~ 10^-7) * 133.322 Pa. It mainly exists in gaseous or aerosol forms in ambient air. Due to their relative large molecular weight, high boiling point, low saturated vapor, they are more difficult to degrade than the volatile organic compounds (VOCs) (benzene, formaldehyde) in the environment with longer time of existence. Additionally, they are easy to be inhaled by human, because it can absorb on the particles. The negative effect of SVOC on human reproduction and genetic system is a long-term and persistent hazard across generations. The impact of SVOC on the environment has been increasing year by year with broadening scope. Hence, it is important to determine the SVOC that present in soil, water and air, especially some semivolatile petroleum products of which most are polycyclic aromatic hydrocarbons (PAH). These polycyclic aromatic hydrocarbons that contain two or more benzene rings enter into the environment mostly because of the incomplete burning of oil. It is one of the earliest discovered organic pollutants which are carcinogenic, teratogenic and mutagenic. Its carcinogenicity increases with the increase of the number of benzene ring. What's worse, they can generate PAH derivatives with more carcinogenicity when they react with the nitro, hydroxy and amino.

Alfa Chemistry has a wealth of experience in the detection of semivolatile petroleum products, and we devote to be a world leader in the field of oil & gas analysis. We can provide a broad range of method to determine the semivolatile petroleum products at the same time ensure the accuracy of the measurement results in a relatively short period of time using advanced instruments.

The method of semivolatile petroleum products test

• 1. Ultra-sonic extraction

Ultrasonic extraction uses the strong cavitation by the ultrasonic radiation pressure, mechanical vibration, high acceleration, diffusion, crushing and stirring function to increase the solvent penetration and material molecular motion frequency and speed, and then accelerate the target component into the solvent and promote the process of extraction.

• 2. Thermal desorption - gas chromatography/mass spectrometry

These semivolatile petroleum products have different boiling points range between approximately 240 °C and 400 °C. Hence, we can use gas chromatogram to determine the content of each component. Compared with the traditional organic solvent extraction method [1], the recovery rate and precision of thermal desorption method are a bit poor. However it reduces the loss and dilution of the sample with no solvent extraction process. In summary, the detection limit of thermal desorption is significantly better than organic solvent extraction method and the process rarely need solvent, which is harmless to the human body and the environment.

We shall be greatly honored to provide you high-quality oil and gas tests. Feel free to contact us at any time. Our professional team will be glad to listen to your concerns and look forward to cooperating with you.

Reference

• X, X, Wang, Q, Y, Liu. Determination of 16 polycyclic aromatic hydrocarbons in airborne particle samples using two-step thermal desorption and gas chromatography- mass spectrometry [J]. Chinese Journal of Chromatography, 2010,28(9): 849~853.