선택한 단어 수는 입니다.
최소 단어 이상 선택하여야 합니다.
최소 단어 이상 선택하여야 합니다.
선택한 단어 수는 30입니다.
최대 10 단어까지만 선택 가능합니다.
최대 10 단어까지만 선택 가능합니다.
가설 설정
- 6. and Table 7. In the case of phenol and p-cresol, sensitivities (defined as the slope of the calibration curve) were relatively lower than those of indole and skatole. On the contrary, the sensitivity of skatole was indicated to be highest.
제안 방법
- The SPME fibers were conditioned as recommended by the manufacturer prior to their first use. In order to find the stability of each adsorption time period, we designed an experiment with fiber extraction time periods of 10, 20 and 30 minutes before thermal desorption. The results demonstrated that as time increased so did the amount of indoles extracted by SPME fiber, but prolonged extraction time decreased experimental efficiency.
- In order to study the usefulness of Tenax-TA for analyzing indoles in swine facility, 50 L, 100 L and 200 L of the air of the pig house (A) were passed through the Tenax tubes by use of a portable vacuum pump with a set flow rate of 5.0 Lmin-1. Total amount of air passing the tube was measured with a dry gas meter (DC-1 Kawasaki, Japan) that was connected to the outlet of the sorbent tube.
- The combination of extraction time, reaction temperature and sample air are the essential factors determining the extraction conditions. Instead of finding the optimal extraction conditions, our goal for this experiment was to develop a feasible and reproducible extraction condition for indoles analysis of the air of swine facility. The equilibrium state of the SPME is described by the equation below (Yo, 1999).
- The adsorbed fiber was then retrieved into the needle of the fiber assembly. The detection limit study was carried out by performing seven replications of samples at the concentration of the lowest calibration point. All laboratory and field sampling were carried using three replications.
- Thus, we attempted to compare the two sampling methods of indoles in airs from swine facilities ; one is the adsorption of indoles in airs to Tenax tube, desorption by automatic thermal desorber and consequently gas chromatographic analysis and the other is collection of indoles in airs desorption into gas chromatography, and suggest the usefulness of usefulness of each method.
- To test the effectiveness of SPME fibers in extracting indoles of the standard solution in a 20 ml vial, four SPME fibers (100 mm PDMS, 75 mm CAR/PDMS, 65 mm PDMS/DVB and 65mm DVB/ CAR/PDMS) were utilized in a preliminary investigation. The SPME fibers were conditioned as recommended by the manufacturer prior to their first use.
대상 데이터
- The detection limit study was carried out by performing seven replications of samples at the concentration of the lowest calibration point. All laboratory and field sampling were carried using three replications.
- Preconditioned Tenax-TA tubes (Supelco Cat. No.:25055) were purchased from Supelco for collecting indoles in airs from swine facilities. Before the first use, sorbent tubes were conditioned by thermal desorption under a 100 mL/min flow of N2.
- The SPME system, including reaction vials, extraction stand, holder, and fibers (100 mm Polydimethylsiloxane (PDMS), 75 mm Carboxen/Polydimethylsiloxane (CAR/ PDMS), 65 mm Polydimethylsiloxane/Divinylbenzene (PDMS/DVB), Divinylbenzene/ Carboxen/Polydimethylsiloxane (DVB/CAR/ PDMS)) were purchased from Sigma- Aldrich Korea. The indole from SPME were analyzed by Varian 450 Gas Chromatograph equipped with mass detector (Varian 220MS).
- The SPME system, including reaction vials, extraction stand, holder, and fibers (100 mm Polydimethylsiloxane (PDMS), 75 mm Carboxen/Polydimethylsiloxane (CAR/ PDMS), 65 mm Polydimethylsiloxane/Divinylbenzene (PDMS/DVB), Divinylbenzene/ Carboxen/Polydimethylsiloxane (DVB/CAR/ PDMS)) were purchased from Sigma- Aldrich Korea. The indole from SPME were analyzed by Varian 450 Gas Chromatograph equipped with mass detector (Varian 220MS). The compounds were separated on a fused silica SPB-608 capillary column (30 m × 0.
- Phenol and p-cresol are basically phenolic substances which was allocated to the category of indoles due to their similar physical/adsorption characteristics and the possibility of a simultaneous chromatographic determination together indole and skatole. They were obtained from Duksan Chemical in Korea (Junsei 99% GR, phenol) and AldrichKorea (p-cresol, indole and skatole), and 99.5% ethanol (Wako Pure Chemicals Industries, Ltd.) for dissolving indoles was obtained from Duksan Chemical (Seoul, Korea). All standards were used as received.
- Fresh air was provided by forced ventilation fans. Three locations at the facility were chosen for sampling sites: 1.5 m above the floor in the house (sampling point A), at the outlet of the exhaust fan (sampling point B) and at the borderline of the pig house (sampling point C). Temperatures, humidities and wind speeds at sampling sites are presented in Table 4.
성능/효과
- In conclusion, the polyester bag sampling of swine airs and SPME extraction of indoles is simple and effective, compared to adsorption in Tenax-TA tube. For SPME fiber, PDMS/DVB is adequate for extracting indoles in a swine facility.
- In order to find the stability of each adsorption time period, we designed an experiment with fiber extraction time periods of 10, 20 and 30 minutes before thermal desorption. The results demonstrated that as time increased so did the amount of indoles extracted by SPME fiber, but prolonged extraction time decreased experimental efficiency. In this study, 30 minutes was chosen as the extraction time for indoles.
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