Abstract: A rapid detection method of sulfide content is provided, which includes determining the concentration and volume of a metal ion solution, the volume of a sample, and the amount of a chemical reducing agent, depending on a threshold value. It also provides preparing the metal ion solution, sampling the sample, and mixing the metal ion solution with the sample to result in a mixture solution. The chemical reducing agent is added into the mixture solution to obtain the resulting solution. Naked-eye observation of the resulting solution is used to determine whether the sulfide content of the sample is over the threshold value. When the resulting solution is clear, this indicates that the sulfide content of the sample is greater than or equal to the threshold value. When the resulting solution contains precipitates, this indicates that the sulfide content of the sample is lower than the threshold value.

Abstract: method for diagnosing corrosion of an underground storage tank system is provided. The method includes the following steps. A sample from the underground storage tank system is collected, wherein the sample comprises at lease one metal ion. The species and the concentration of the metal ion in the sample are detected by an analysis instrument. A concentration threshold value is determined from a database according to the species of the metal ion. A mapping step is performed, wherein the concentration of the metal ion and the concentration threshold value are compared to diagnose if the underground storage tank system is corroded.

Abstract: A method for analyzing the liquefied petroleum gas includes the following steps. Provide a sample of the liquefied petroleum gas, and one main component group of the liquefied petroleum gas includes at least one sub component group. Analyze the sample of the liquefied petroleum gas so as to obtain a first measured THC corresponding to the main component group and a second measured THC corresponding to the sub component group. Obtain a regressed THC according to the second measured THC and a predetermined relationship of THC. Obtain a result of THC according to the first measured THC, the regressed THC, and a predetermined range of THC. The predetermined range of THC corresponds to the main component group. The device for analyzing the liquefied petroleum gas includes an inlet, a multiposition valve, a first column, a second column, an analyzing apparatus, and a computing unit.

Abstract: A method for diagnosing corrosion of an underground storage tank system is provided. The method includes the following steps. A sample from the underground storage tank system is collected, wherein the sample comprises at lease one metal ion. The species and the concentration of the metal ion in the sample are detected by an analysis instrument. A concentration threshold value is determined from a database according to the species of the metal ion. A mapping step is performed, wherein the concentration of the metal ion and the concentration threshold value are compared to diagnose if the underground storage tank system is corroded.

Abstract: A method for analyzing the liquefied petroleum gas comprises the following steps. Provide a sample of the liquefied petroleum gas, and one main component group of the liquefied petroleum gas comprises at least one sub component group. Analyze the sample of the liquefied petroleum gas so as to obtain a first measured THC corresponding to the main component group and a second measured THC corresponding to the sub component group. Obtain a regressed THC according to the second measured THC and a predetermined relationship of THC. Obtain a result of THC according to the first measured THC, the regressed THC, and a predetermined range of THC. The predetermined range of THC corresponds to the main component group. The device for analyzing the liquefied petroleum gas comprises an inlet, a multiposition valve, a first column, a second column, an analyzing apparatus, and a computing unit.

Abstract: The invention provides a method for determining fuel quality and ethanol content. A mobile fuel analysis apparatus including a vehicle is provided. A database includes near-infrared spectra of standard fuel from a plurality of suppliers to establish correlation between quality parameter and the spectra of the oils. A near-infrared spectrometer is equipped on the vehicle and transported to a fuel distribution point. A near-infrared spectrum of a fuel sample is collected from the fuel distribution point. The collected spectrum is compared to the near-infrared spectra in the database, and converted into corresponding quality parameters.

Abstract: The invention provides a method for determining fuel quality. A mobile fuel analysis apparatus comprising a vehicle is provided. A database comprises near-infrared spectra of standard fuel from a plurality of suppliers to establish correlation between quality parameter and the spectra of the oils. A near-infrared spectrometer is equipped on the vehicle and transported to a fuel distribution point. A near-infrared spectrum of a fuel sample is collected from the fuel distribution point. The collected spectrum is compared to the near-infrared spectra in the database, and converted into corresponding quality parameters.

Abstract: A method for automatically detecting waste gas. The waste gas is led into a multiple switching valve through which the waste gas is sampled. Then, the waste gas sample is conveyed to an empty column and/or a chromatographic column, via the multiple switching valve. Then, the total hydrocarbon content of the waste gas sample is measured when the waste gas sample is conveyed to the empty column, and the waste gas sample is separated for measuring individual volatile organic compound concentrations of the waste gas sample when the waste as sample is conveyed to the chromatographic column.