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A new method was established for the determination of extractable flame retardants (FRs) from textile, foam, leather and plastic test specimens. The FRs were extracted with toluene from test specimens using ultrasonic-assisted extraction with an extraction time of 60 min at 60ºC. FRs were separated on a DB-XLB column using gas chromatography-mass spectrometry (GC-MS) with helium (99.9%) as a carrier gas. One target and two qualifier ions were selected for target analyte under SIM/SCAN mode. Pre-treatment parameters were optimised, including the type of extractant, extraction method and extraction time. Under optimised conditions, recoveries of target compounds ranged from 90% to 100.8%. Calibration curve working range was from 0.25 to 5.0 mg L−1 with regression value 0.996–0.998. Relative standard deviation was <15% for test specimens and <10% for pure standards, respectively. Limit of detections were lower than 0.02 mg L−1 level. The proposed method was successfully used for the determination of actual specimens with concentrations ranging from 1.20 to 18.34 mg L−1. [ABSTRACT FROM AUTHOR]

The phenolic compounds and antioxidant activities of natural plant extract have the ability to maintained human health and reduced the risk of disease. The present study investigates the feasibility of the ultra-sonic assisted extraction method and most effective solvents for the extraction of phenolic, flavonoid, and antioxidant activities of freeze-dried pomegranate seed powder. The study also involved investigations of physicochemical characteristics such as edible & waste index, acidity, TSS, moisture, and pH of pomegranate fruits, seed, and dried powder. The pomegranate seed powder was subjected to extraction using five different polar and nonpolar solvents viz., methanol, ethanol, water, acetone, and hexane. In this study, the methanol solvents exhibit the highest value of phenolic contents (18.25 mg/g), flavonoid contents (9.13 mg/g), and antioxidant activity (89.39%). The antioxidant (DPPH), phenolic and flavonoid content activity were analyzed by using standard methods. The physicochemical properties depend on the types of solvents that extract compounds according to polarity and nonpolarity. The obtained results were indicated that the methanol solvent is significantly effective (P <.05) for quality extraction of phenolic and flavonoid contents with high antioxidant activity of pomegranate seed powder. [ABSTRACT FROM AUTHOR]

Substantial amount of apple pomace (AP) is produced in apple processing industries and is often discarded as waste which becomes a source of polluting the environment. However, the by-product constitutes a promising bioresource of ursolic acid with various biological activities. Therefore, this particular research study was aimed to develop a novel and facile method to separate ursolic acid from AP. First, AP was extracted with ultrasound assistance using methanol as extraction solvent, 2.86% with 10:1 (mL g−1) of liquid–solid ratio, 300 W of ultrasonic power, 50°C of extraction temperature, and 90 min of ultrasonic time. Meanwhile, the disruption effect of ultrasound on AP was observed by scanning electron microscope. Second, a novel and facile method was applied to separation of ursolic acid, then a perfect colorless needle crystal of ursolic acid was obtained with the yield of about 1.34% of dry AP. [ABSTRACT FROM AUTHOR]

A simple, highly sensitive and environment-friendly method, combined with flame atomic absorption spectroscopy (FAAS) is developed to preconcentrate and determine trace amounts of thallium in aqueous solutions. In the preconcentration step, the thallium (I) from 30 mL of an aqueous solution was extracted into 350 µL of ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate [Hmim][PF6], containing dicyclohexyl-18-crown-6 (DCH-18-crown-6) as complexing agent. Subsequently, the DCH-18-crown-6 complex was back-extracted into 300 µL of nitric acid (2 mol L−1) solution, and analyzed by FAAS. Several parameters influencing the extraction and determination of thallium, such as pH, concentration of DCH-18-crown-6, sonication and centrifugation times, sample volume, ionic liquid amounts, ionic strength, and concentration of stripping acid solution, were optimized. Under optimum conditions, the calibration graph was linear in the range of 5 to 400 ng mL−1, the detection limit was 0.64 ng mL−1(3Sb/m,n = 7), the enhancement factor was 98.2 and the relative standard deviation was ±1.43%. The results for preconcentration and determination of trace amount of thallium in waste water, well water, tap water, sea water, human hair and nail demonstrated the accuracy, recovery and applicability of the presented method. [ABSTRACT FROM PUBLISHER]

A method for the analysis of chlorotoluenes (CTs) in soil has been developed based on ultrasonic assisted extraction with a low volume of organic solvent and determination by gas chromatography-tandem mass spectrometry (GC–MS/MS). A simultaneous clean-up on an alumina–anhydrous sodium sulphate mixture was carried out to remove soil interferences. However, an additional clean-up with graphitised carbon was needed for some very dirty samples. Several solvents were assayed and a mixture of ethyl acetate:hexane (80 : 20, v/v) was selected to carry out soil extractions. Recovery studies were performed at 0.2, 0.1, 0.05 and 0.02 ng g−1 fortification levels, and recoveries obtained for all the compounds and concentrations were higher than 81% with standard deviations fulfilling the requirements of the IUPAC. LODs from 0.7 to 5.2 ng kg−1 and LOQs from 2.2 to 17.5 ng kg−1 were achieved for the analysed compounds, being pentachlorotoluene the compound with the highest limits, followed by the monochlorinated toluenes. The proposed analytical method was applied to determine CT levels in agricultural and industrial soils. These compounds were found in all the industrial soils analysed and some CTs were present in agricultural soils at lower levels. [ABSTRACT FROM AUTHOR]