Method for determining oil mist in workshop air by non-dispersive infrared process

Abstract

The invention provides a method for determining oil mist in workshop air by a non-dispersive infrared process, which comprises the following steps: collecting oil mist in workshop air, transferring the collected sample into a color comparison tube, adding a solvent incapable of absorbing infrared radiation to carry out extraction, determining the extracting solution by a non-dispersive infrared process, recording the absorbance at the wavelength of 3.400 mu m in the infrared spectrum, and acquiring the content of oil mist according to an external standard method. The method provided by the invention has the advantages of high accuracy, high speed, small interference and high sensitivity, and the precision and accuracy are respectively less than 5%, thereby satisfying the demands of people for detection work and research. The invention fills up the blank of the method for determining oil mist in workshop air by a non-dispersive infrared process.

Description

technical field [0001] The invention relates to a non-dispersive infrared method for measuring oil mist in workshop air, in particular to a non-dispersive infrared method for measuring oil mist in workshop air. Background technique [0002] Lubricating oil is an important raw material used in industries such as mechanical processing, heat treatment and transportation. Its main components are hydrocarbons, and usually contain a small amount of polycyclic aromatic hydrocarbons and heterocyclic compounds. It exists in the state of oil mist in the air of the workshop . With the development of industrial modernization, the environment of oil mist in the air of workshops is increasing, and the health hazards of oil mist to employees have become increasingly prominent. However, my country has not yet established a standard detection method for oil mist in workshop air. Therefore, it is imminent to study the detection method of oil mist in workshop air. [0003] At present, the de...

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Problems solved by technology

[0004] CN201210287112.0 discloses a method for measuring the concentration of mineral oil mist in the workshop air. The method uses CCl 4 2700-3200cm for reference -1 Infrared scanning, take the measured maximum absorption peak as the measurement wavenumber of the sample, and subtract 3200cm from the maximum absorption peak absorbance -1 The absorbance of the sample concentration is used to draw a standard curve, which is determined according to the external standard method, but the maximum absorption peak often has shoulder peaks, broad peaks or double peaks, etc., which need to be divided into peaks, and the spectrum processing is more complicated; Chinese national standard HJ637-2012 "Water Quality Petroleum and Animal and Vegetable Oil Determination Infrared Spectrophotometry" and CN201110138832.6 both disclose a kind of infrared photometry for measuring oil in water, the method extracts oil in water by carbon tetrachloride, and uses infrared spectroscopy The extract is at 2930cm -1 、2960cm -1 、3030cm -1 The infrared absorption determines the mass-volume concentration of total oils, and carbon tetrachloride belongs to chlorofluoroalkane, which destroys the ozone layer and is a chemical substance that is restricted in production and banned in large quantities in the international convention "Montreal Protocol on Substances that Deplete the Ozone Layer"; CN201010222421 .0 discloses a method for determining water quality petroleum. The extraction process of this method requires the sample to be extracted 2 to 5 times with dichloromethane under alkaline and acidic conditions. The operation process is complicated and the pretreatment time is long; CN201210041697. 8 discloses a method for detecting mineral oil in sludge. This method uses petroleum ether ultrasonic extraction, and the ultraviolet spectrophotometer is set at a wavelength of 225nm. It is determined according to the absorbance external standard method, but the method can only measure components and chromophore organic compounds with n electrons, but saturated hydrocarbons cannot be detected, and when the number of aromatic hydrocarbons in the oil components is different, the resulting absorbance varies greatly, so the measurement results are not representative

US8222605B2 discloses a kind of mid-infrared spectrometry to measure the total acid value and naphthenic acid value of petroleum in water, but the applicable scope of this method is the sample that the oil content in water is lower than 15%