Determination of polycyclic aromatic hydrocarbons in marine sediments by high-performance liquid chromatography after microwave-assisted extraction with micellar media.
A simple and rapid method is developed for extraction and determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. The procedure was based on the microwave-assisted extraction of PAHs in marine sediment samples using a micellar medium of Polyoxyethylene 10 lauryl ether as extractant. Two-level factorial designs have been used to optimize the microwave extraction process. The analysis of extracts has been carried out by HPLC with UV detection. Fortified sediments gave an average recovery between 85.70 and 100.73%, with a relative standard deviation of 1.77-7.0% for PAHs with a ring number higher than three.
A cost effective, sensitive, and environmentally friendly sample preparation method for determination of polycyclic aromatic hydrocarbons in solid samples.
A simple, cost effective, and yet sensitive sample preparation technique was investigated for determining Polycyclic Aromatic Hydrocarbons (PAHs) in solid samples. The method comprises ultrasonic extraction, Stir Bar Sorptive Extraction (SBSE), and thermal desorption-gas chromatography-mass spectrometry to increase analytical capacity in laboratories. This method required no clean-up, satisfied PAHs recovery, and significantly advances cost performance over conventional extraction methods, such as Soxhlet and Microwave Assisted Extraction (MAE). This study evaluated three operational parameters for ultrasonic extraction: solvent composition, extraction time, and sample load. A standard material, SRM 1649 a (urban dust), was used as the solid sample matrix, and 12 priority PAHs on the US Environmental Protection Agency (US EPA) list were analyzed. Combination of non-polar and polar solvents ameliorated extraction efficiency. Acetone/hexane mixtures of 2:3 and 1:1 (v/v) gave the most satisfactory results: recoveries ranged from 63.3% to 122%. Single composition solvents (methanol, hexane, and dichloromethane) showed fewer recoveries. Comparing 20 min with 60 min sonication, longer sonication diminished extraction efficiencies in general. Furthermore, sample load became a critical factor in certain solvent systems, particularly MeOH. MAE was also compared to the ultrasonic extraction, and results determined that the 20-min ultrasonic extraction using acetone/hexane (2:3, v/v) was as potent as MAE. The SBSE method using 20 mL of 30% alcohol-fortified solution rendered a limit of detection ranging from 1.7 to 32 ng L(-1) and a limit of quantitation ranging from 5.8 to 110 ng L(-1) for the 16 US EPA PAHs.
Extraction and Quantitation of Polyolefin Additives
Abstract The extraction and subsequent separation and quantitation of polymer additives in polyolefins has proven to be a challenge for the analytical chemist. There have been several workers over the years who have investigated the separation of additives in polyolefins (1–7), but the extraction and recovery (at > 90%) in reasonable times has been most difficult. the Soxhlet extraction technique has been used for many years, but suffers in that it takes over twelve hours to extract most of the additives used in polyolefin formulations. Some workers have used the ultrasonic bath (7), but not very much work has been done with the microwave oven. We have investigated some ways to extract the additives from polyolefins, namely, microphye oven and ultrasonic bath techniques for high density polyethylene (HDPE), low density polyethylene (LDPE), and polypropylene. We have concentrated on identifying and quantitating recoveries for typical polyolefin antioxidants, 20 such as Irganox 1010, Irgafors 68, and Cyasor...