Focused ultrasound solid–liquid extraction for the determination of organic biomarkers in beachrocks

Abstract

Beachrocks are consolidated coastal sedimentary formations resulting mainly from the relative rapid cementation of beach sediments by different calcium carbonate polymorphs. Although previous works have already studied the elemental composition and the mineral phases composing these cements, few of them have focused their attention on the organic matter present therein. This work describes an extraction methodology based on focused ultrasound solid-liquid extraction (FUSLE), followed by analysis using large volume injection (LVI) in a programmable temperature vaporizer (PTV) combined with gas chromatography-mass spectrometry (GC-MS) in order to determine organics such as polycyclic aromatic hydrocarbons (PAHs) and biomarkers (hopanes), which can increase and confirm the information obtained so far. This goal has been achieved after the optimization of the main parameters affecting the extraction procedure, such as, extraction solvent, FUSLE variables (amplitude, extraction time and pulse time) and also variables affecting the LVI-PTV (vent time, injection speed and cryo-focusing temperature). The developed method rendered results comparable to traditional extraction methods in terms of accuracy (77-109%) and repeatability (RSD<23%). Finally, the analyses performed over real beachrock samples from the Bay of Biscay (Northern Spain) revealed the presence of the 16 EPA priority PAHs, as well as some organic biomarkers which could increase the knowledge about such beachrock formation.

An Overview of Analytical Methods to Determine Pharmaceutical Active Compounds in Aquatic Organisms

“…By introducing a probe directly into the extraction mixture, a sonication power up 100 times higher is achieved, as well as greater reproducibility and efficiency. The ultrasound energy is concentrated at the tip of the probe and is hence focused [ 83 ], and when ultrasound waves cross the liquid, many gaseous bubbles are formed which, when they implode, produce locally very high temperatures as well as high pressures and velocities of solvent micro-jets [ 84 ]. Mijangos et al used FUSLE to extract antibiotics, analgesics and antiepileptics, among others from mussels and sea bream.…”

In situ organic biosignature detection techniques for space applications

“…Relatively short processing times, less than a few minutes, are typically applied to avoid analyte degradation. It has been shown that UAE can be as efficient as the traditional Soxhlet extraction technique for PAHs and hopanes (Blanco-Zubiaguirre et al, 2015), and that it is more efficient than microwave-assisted extraction for multiple organic biosignatures (Timoumi et al, 2022). UAE is a part of most current biosensor instruments designed for solid samples (see Section 5.3).…”

Ultrasound assisted extraction for the determination of mercury in sediment samples employing cold vapour atomic absorption spectrometry

“…7 Blanco-Zubiaguirre et al established an extraction procedure using focused ultrasound for the determination of 16 polycyclic aromatic hydrocarbons (PAHs) and biomarkers (hopanes) in beachrock samples. 8 A method proposed by Johnston et al determined twelve polycyclic aromatic hydrocarbons (PAHs) in contaminated sediments. The extraction was performed using ultrasound assisted radiation.…”