• Analytical Science and Technology
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• v.15 no.4
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• pp.360-364
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• 2002

The most common 8 phthalic acid esters (PAEs) and adipate in sediment were measured 5 times from 1999 to 2001 at 11 sites of river in Korea. Ultrasonication extraction with dichloromethane was done for extraction of the sediment. After concentration GC/MS-SIM analysis was performed. Three compounds (DEP, DBP and DEHP) among eight phthalic acid esters were detected from the sediment samples, and the other PAEs were not detected in any samples. DEHP (27.3~63.6%) was detected with higher frequency than any other compounds for sediment samples. And this compound had shown the highest average concentration (81.7~427.6 ng/g).

• The Korean Journal of Food And Nutrition
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• v.13 no.4
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• pp.334-341
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• 2000

The DMPT produced by marine algae is the main biogenic precursor of oceanic DMS. Also, DMPT is an efficient stimulant for growth, feeding, and body movement of fish and striped prawn, and appears to play a physiologic role as an osmoprotectant in algae. This study was focused on the extraction of dimethyl-$\beta$-propiothetin as bioactive substance from green seaweed. Identification and quantification of dimethyl-$\beta$-propiothetin were measured by headspace gas chromatography after conversion to dimethyl sulfide by treatment with saturated NaOH solution. Dimethyl-$\beta$-propiothetin was extracted through various processes(solvent extraction, ultrasonication, boiling and autoclaving) from Enteromorpha intesinalis. The content of dimethyl-$\beta$-propiothetin extracted by autoclaving treatment showed higher than those of various extraction methods. Dimethyl-$\beta$-propiothetin content in extract of Enteromorpha Enteromorpha was 311,200ng/g after autoclaving at 121$^{\circ}C$ for 60min. Dimethyl-$\beta$-propiothetin in extract of Enteromorpha intestinalis was comparatively stable under low temperature. The retentions of dimethyl-$\beta$-propiothetin content in extract of Enteromorpha intestinalis were 75.8 ~99.8% by incubation at 10~6$0^{\circ}C$ for 2 hours. Chemical decomposition of dimethyl-$\beta$-propiothetin was observed under laboratory conditions at pH values higher than 9.5.

• Journal of Korean Ophthalmic Optics Society
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• v.15 no.3
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• pp.227-234
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• 2010

Purpose: The cleaning effect of protein deposit and the change of contact lens parameters by ultrasonic cleaner for eye glasses on the soft contact lenses were investigated. Methods: Etafilcon A contact lenses contaminated with protein, was ultrasonicated by ultrasonic cleaner for eye glasses and for the control group, spoiled contact lenses were cleaned by multi-purpose solution. The remaining protein deposits on the contact lenses were determined after extraction and the changes of overall diameter, base curve, center thickness power, and water contents on contact lenses were measured and surfaces of contact lenses were observed by scanning electron microscope. Results: The cleaning efficacies of multi-purpose solution on protein deposited etafilcon A contact lenses were 6.08%, and 23.73~33.92% in the group of ultrasonic cleaner for eye glasses with multi-purpose solution and 0~12.99% in the group of ultrasonic clear for contact lens with multipurpose solution depending on the treatment time. The changes of parameters and surface on contact lenses by ultrasonication were not observed. Conclusions: Ultrasonic cleaner for eye glasses can be used to eliminate protein deposits for the diagnostic soft contact lens in the office since it was effective to eliminate protein deposits and not caused change of parameters on soft contact lenses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.359-363
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• 2009

This study was performed to establish a rapid and simple analytical method for niacin (nicotinic acid and nicotinamide) using HPLC. A pretreatment method for the extraction and clean-up of niacin in infant formula sample and an instrumental condition for HPLC were optimized. Niacin was extracted by 5 mM hexanesulfonate with ultrasonication for 30 min. For the clean-up of the sample, the extract was applied to a HLB cartridge, and then niacin was eluted from the cartridge using 5 mL of 80% methanol after washing with 5 mL of n-hexane. The total recoveries were $83{\sim}104%$ and relative standard deviation were in the range of $1.5{\sim}3.5%$ during the extraction and clean-up process. Niacin was determined by gradient elution with sodium hexanesulfonate/methanol buffer as a mobile phase and a photodiode array detector (260 nm). It showed a high linearity between the content of niacin and the peak area ($r^2$=1.000) in the range of $0.02{\sim}10.0$ mg/L of nicotinic acid and nicotinamide. The detection limit was 0.02 mg/L (0.2 mg/kg in the sample). The method was successfully applied for the determination of niacin in infant formula. Total niacin contents were in the range of $53.5{\sim}140.3$ mg/kg.

• Applied Biological Chemistry
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• v.37 no.5
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• pp.409-413
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• 1994

Barbaloin in the Aloe vera depending on the various extracting conditions was analyzed by HPLC. The contents of the barbaloin extracted by the solvents increased in the order of methanol>ethanol>water extraction. In setting extraction, the contents of barbaloin extracted with methanol and ethanol were increased from four hours at $60^{\circ}C$ and then decreased. The contents of barbaloin extracted with water were different depending on the temperature and time. Increasing the extracting time and temperature, the contents of barbaloin were decreased in water extract. It was estimated that the barbaloin might be stable in organic solvent, but decomposed with hydrolysis in water.

• Journal of Life Science
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• v.22 no.12
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• pp.1665-1671
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• 2012

This study was conducted to assess the removal of residual pesticides and to obtain high amounts of quercetin in onion peel extracts (OPEs) by 4 washing treatments. Washing is one of the standard processing steps in obtaining functional food ingredients from onion peel. After a first detergent wash (0.2% w/v) (DW) and hot air drying ($80^{\circ}C$, 24 hr) (B), 4 washing treatments were tested, including a second DW (C), ultrasonication ($50^{\circ}C$, 10 min) plus DW (D), 0.3% $H_2O_2$ (v/v) plus DW (E), and blanching ($95-97^{\circ}C$, 2 min) plus DW (F). This was followed by 60% (v/v) ethanol extraction and vacuum freeze drying of the OPE. The E treatment yielded 89.04% OPE and a quercetin content of 96.84% in the OPE compared with the B treatment, and had the highest efficiency of all treatments tested. The OPE was tested for the presence of 177 residual pesticides and three compounds were detected in all treatments: cyhalothirn, fluquinconazole and procymidone. Cyhalothirn and fluquinconazole levels were below the permitted levels for fresh onion, while procymidone was present in the high level range of 128.01~133.46 mg/kg in all samples. The E treatment was a better washing method than the others for removal of residual pesticides. It could reduce the level of residual pesticides without changing the functional properties of the OPE.