• Journal of Korean Society of Environmental Engineers
• /
• v.37 no.5
• /
• pp.293-302
• /
• 2015

Halonitromethanes (HNMs) are one of the most toxic groups of disinfection by-products. Recently, various studies have been fulfilled. An automated headspace-solid phase microextraction (SPME) gas chromatography/electron capture detector (GC-ECD) technique was developed for routine analysis of 9 HNMs in water samples. The optimization of the method is discussed. The limits of detection (LOD) and limits of quantification (LOQ) range from 90 ng/L to 260 ng/L and from 270 ng/L to 840 ng/L for 9 HNMs, respectively. Matrix effects in tap water and sea water were investigated and it was shown that the method is suitable for the analysis of trace levels of HNMs, in a wide range of waters. The method developed in the present study has the advantage of being rapid, simple and sensitive.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.2
• /
• pp.302-304
• /
• 2006

• Korean Journal of Food Science and Technology
• /
• v.25 no.1
• /
• pp.52-56
• /
• 1993

Flavor compounds formed in the ramyon fried in palm oil at $148-150^{\circ}C$ for 1 minute during storage at $65^{\circ}C$ were isolated and identified by gas chromatography-mass spectrometry. Their changes in the amount when the ramyon was stored at 20, 40 and $65^{\circ}C$ were also studied by using static headspace gas chromatography. Pentane, hexane, butanal, heptane, 1-pentanol, hexanal, and octane were formed during $65^{\circ}C$ storage of the ramyon and they were thought to be from linoleic and oleic acid present in ramyon. Formation of the flavor compounds was shown to increase with the storage temperature and/or storage time. Hexanal showed the highest correlation with the sensory score(r=0.87).

• Analytical Science and Technology
• /
• v.29 no.5
• /
• pp.242-247
• /
• 2016

This research aims to set up and validate methods of analyzing the methanol in wet wipes and verifies the analysis methods that applied to the wet wipes. We used Headspace (HS) Gas Chromatography (GC) - Flame Ionization Detector (FID) to the establish analysis method of methanol in wet wipes and optimized heating temperature, heating time, GC conditions with column. The result indicated that 3 mL of sample in 20 mL headspace vial can be equilibrated efficiently in headspace sampler at 70 ℃ for 10 min and sample was measured by GC with spli injection mode(10:1). The results show that linearity from 1 to 100 ppm was over R2 0.9995, precision was RSD 1.83 % and accuracy(recovery rate) was 105.44 (±1.05 %) on water matrix and wet wipes matrix removed non-woven fabric. Also, monitoring results of total 20 cosmetics on the market, from 0.00017 to 0.00156 % of methanol was detected from wet wipes.

• Korean Journal of Food Science and Technology
• /
• v.17 no.5
• /
• pp.406-408
• /
• 1985

n-Hexanal in headspace over the cooked brown rice stored at $5^{\circ}C$ and $35^{\circ}C$ for 0. 4, 8 and 12 months was determined by a modified direct vapor injection gas chromatographic method. The retention time of n-hexanal was 3.5 min and n-hexanal could be rapidly separated from other compounds at the operational conditions of gas chromatography. n-Hexanal contents of cooked brown rice also showed a standard deviation of less than 10% of the average.

• Analytical Science and Technology
• /
• v.27 no.1
• /
• pp.22-26
• /
• 2014

1,4-Dioxane was classified as a Group 2B carcinogen by the International Agency for Research on Cancer. The compound was measured in surface water with a headspace gas chromatographic mass spectrometric detection. A 5 mL water sample was placed in a 10 mL headspace vial and saturated with NaCl, and the solution was spiked with 1,4-dioxane-d8 as an internal standard and sealed with a cap. Water samples were collected from twenty-two basins of Gum-River on June and September 2012, respectively. As a result, 1,4-dioxane was detected in the concentration range of $0.49-43.0{\mu}g/L$ (mean $2.0{\mu}g/L$) in the frequency of about 30% in surface water samples.

• Journal of the Korean Applied Science and Technology
• /
• v.15 no.4
• /
• pp.63-69
• /
• 1998

The beeswax sample was collected from the beehives, isolated and then refined. The first step of producing beeswax was to separate honey from beehives. The beehives which were cut put in hot water. The upper layer was crude beeswax, which was treated with phosphoric acid. The crude beeswax was purified through the bleaching. The objectives of this study are to identify headspace volatile compounds and to know the contents of ${\alpha}$-carotenes and ${\beta}$-carotenes of korean beeswax. Headspace volatile compounds of Korean beeswax were measured by using the combination of dynamic headspace sampler (DS 5000, Donam System Inc.), gas chromatography and mass selective detector (HP5890 & 5971, Hewlett Packard). Seventy five compounds identified from about 100 peaks by analyzing the purified beeswax were 60 hydrocarbons, 8 carbonyls, 4 essential oils, 3 esters. Carotenes of Korean beeswax were analyzed by using High Performance Liquid Chromatography (Waters Inc.). As A result, the content of ${\alpha}$-carotenes and ${\beta}$-carotenes were 0.07ppm, 0.011ppm individually.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.315-317
• /
• 2004

Henry's law constants of trichloroethylene (TCE) and tetrachloroethylene (PCE) in air-aqueous surfactant systems were determined by gas chromatography headspace analysis of closed system. The effect of surfactant type and concentration was investigated.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2005.10a
• /
• pp.238-239
• /
• 2005

• Preventive Nutrition and Food Science
• /
• v.8 no.4
• /
• pp.315-320
• /
• 2003

Headspace volatile compounds of oxidized fish oil were analyzed by the combination of hexane solvent or solid phase microextraction, gas chromatography and mass selective detector. The optimum condition of headspace analysis by hexane trapping was 23 min absorption time, 96$^{\circ}C$ sample temperature and 20 mL/min air flow rate. The numbers of volatile compounds identified by solvent trapping and SPME were 35 and 14, respectively. Groups having the largest amount and many kinds were hydrocarbons and aldehydes, respectively. The numbers of aldehydes were 15 and 6 for solvent trap and SPME, respectively. These basic data could be used as indicators for the quality changes of fish oil.