On May 30, 2018, the Ministry of Ecology and Environment issued a letter soliciting opinions on three national environmental protection standards: "Determination of Water Quality Petroleum by UV spectrophotometry (draft for comments)", "Determination of Water Quality Petroleum by fluorescence spectrophotometry (draft for comments)", and "Determination of Water Quality Petroleum by Weight (draft for comments)".
It is understood that the current standard in China, "Determination of Water Quality Petroleum and Animal and Plant Oils by Infrared Spectroscopy" (HJ 637-2012), is a revised standard based on the "Determination of Water Quality Petroleum and Animal Oils by Infrared Spectroscopy" (GB16488-1996) promulgated in 1996. This method is currently the standard method for determining oil in water in China's environmental protection industry, using carbon tetrachloride as the extractant.
In December 2017, the "Determination of Water Quality, Petroleum, Animal and Plant Oils by Infrared Spectroscopy" (HJ 637-2012) underwent its second revision. As the current standard method for determining oil in water in China's environmental protection industry, infrared spectrophotometry has high sensitivity, low detection limit, and is not affected by oil products. It can comprehensively detect oil content in water. However, the extractant carbon tetrachloride used is listed as an obsolete substance under the Montreal Convention, and China promises to stop using this method as soon as possible. Therefore, the core of revising this standard is to find alternatives to carbon tetrachloride. The currently revised "Determination of Water Quality, Petroleum and Animal and Vegetable Oils by Infrared Spectroscopy" uses tetrachloroethylene instead of carbon tetrachloride as the extractant. According to the relevant standard preparation instructions released by the Ministry of Ecology and Environment, due to the high purity requirements of tetrachloroethylene and the high detection limit of the newly revised method, it cannot meet the needs of measuring petroleum in Class I-III surface water and Class II seawater. Therefore, there is an urgent need to conduct research on other practical and feasible analysis methods.
According to the letter from the Ministry of Ecology and Environment (formerly the Ministry of Environmental Protection) on the task of verifying and transforming the monitoring and analysis methods for petroleum in water (Huance Bianhan [2017] No. 427), in order to promote the implementation of the Montreal Protocol on Substances that Deplete the Ozone Layer, fulfill China's commitment to stop the use of carbon tetrachloride (CTC) for laboratory purposes in 2019, and meet the monitoring requirements for petroleum in current environmental quality standards and pollutant emission standards, the Environmental Monitoring Department of the Ministry of Ecology and Environment has issued a verification and transformation task for the determination of petroleum in water quality using fluorescence spectrophotometry to the Tianjin Ecological Environment Monitoring Center (formerly the Tianjin Environmental Monitoring Center).
After comparing domestic and foreign petroleum related determination methods, the Ministry of Ecology and Environment issued a letter soliciting opinions on three national environmental protection standards: "Determination of Water Quality Petroleum by UV spectrophotometry (draft for comments)", "Determination of Water Quality Petroleum by fluorescence spectrophotometry (draft for comments)", and "Determination of Water Quality Petroleum by Weight (draft for comments)". The notice states that if relevant units have any opinions, they can provide written feedback to the Ministry of Ecology and Environment before June 15, 2018.

Draft for soliciting opinions on new standards:
1. Water quality - Determination of petroleum - Ultraviolet spectrophotometric method (draft for comments). pdf
2. Compilation Explanation for "Determination of Water Quality and Petroleum by UV spectrophotometry (Draft for Comments)". pdf
3. Water quality - Determination of petroleum - Fluorescence spectrophotometric method (draft for comments). pdf
4. Compilation Explanation for "Determination of Water Quality and Petroleum by Fluorescence Spectrophotometer (Draft for Comments)". pdf
5. Water quality - Determination of oil by weight method (draft for comments). pdf
6. Compilation Explanation for "Determination of Water Quality and Oil by Weight Method (Draft for Comments)". pdf

Principle of Fluorescence Detection:
Fluorescence method is to use the aromatic hydrocarbon components of petroleum to extract with n-hexane, and excite the oil substances in the extraction agent with 310nm as the excitation wavelength to emit fluorescence. The fluorescence intensity at 360nm emission wavelength is measured, and its relative fluorescence intensity is proportional to the concentration of aromatic hydrocarbons in n-hexane. When using fluorescence method for determination, first acidify the water sample, then extract it with n-hexane, and measure the content of petroleum using a fluorescence spectrophotometer.

Applicable instruments:
Turner TD-500D portable water oil analyzer from the United StatesIt is a UV fluorescence oil analyzer that uses n-hexane instead of infrared carbon tetrachloride as the extraction agent. The detection principle is UV fluorescence method (also known as molecular fluorescence method or fluorescence spectrophotometry in China), which meets the technical requirements of the new national standard (draft for comments). It can quickly, easily and reliably measure the oil content in water (crude oil, fuel oil, lubricating oil, diesel, some condensate oil and refined hydrocarbons), with a measurement range of 0.005-1000mg/L. TD-500D has the advantages of small size, light weight, high precision, good reproducibility, simple operation, fast detection speed, and relatively safe and environmentally friendly extractants. It is widely used in the determination of petroleum in surface water, groundwater and sea water such as Rivers and Lakes, industrial sewage, waste water, condensate, and circulating water such as petrochemical, power plants, and steel plants.

Turner TD-550 and TD-560 (portable/desktop) water oil analyzers from the United StatesIt is a newly launched portable and laboratory combined fluorescence oil analyzer and rapid oil analyzer that uses n-hexane instead of infrared method for extracting carbon tetrachloride. It can quickly and reliably detect oil content (petroleum) in water, with a measurement range of 5ppb~5000ppm. Suitable for field emergency monitoring and laboratory routine analysis.TD-550 is suitable for detecting crude oil, marine diesel, heavy fuel oil, and other heavy oils in water, with a significantly increased detection range (5ppb~5000ppm) and performance surpassing most water oil analyzers.On the basis of the same optical channel as TD-550, TD-560 adds a second optical channel for detecting light hydrocarbons. The added oils include: condensate oil, diesel, gasoline, lubricating oil, aviation fuel, kerosene, transformer oil, BTEX benzene derivatives, styrene, phenol, etc.
Turner Hydrocarbon Instrument Company TDHI, USA, is a research and development and production company of advanced hydrocarbon analyzers and water oil monitors, with technology and 30 years of rich experience in the field of UV fluorescence water oil analyzers. The company has developed a complete set of analysis solutions for oil water quality, including portable water oil analyzer TD-500D, desktop water oil analyzer TD-560, and online water oil monitoring devices (TD-120, TD-4100XD, TD-4100XDC). The American Turner water oil analyzer is widely used in petroleum and petrochemical, offshore drilling platforms, industrial enterprises and environmental monitoring, marine and maritime, boiler special inspection and other departments, to help customers improve oil water quality testing technology with excellent product performance.