Method for determining total organic fluorine in water sample and aqueous solution

A technology for the determination of organic fluorine and water, which is applied in the field of determination of total organic fluorine in water based on ultraviolet sulfite pretreatment, can solve the problems of high professional level requirements for operators, unsuitability for widespread popularization and application, and increased processing costs. Achieve the effects of easy sample preparation and detection process, easy determination process, and low processing cost

Inactive Publication Date: 2018-11-16
TSINGHUA UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

Although this method reduces the underestimation of the precursor concentration, the processing cost of the sample will inevitably increase at the same time
[0008] At present, the increase of sulfite concentration is beneficial to increase the amount of hydrated electrons of active species, and the degradation rate and defluorination rate of PFOS are increased accordingly. The concentration of sulfite increases from 1mmol L~(-1) to 20mmol L~( -1), the PFOS degradation rate and defluorination rate increased from 45% and 40% to 97% and 63% respectively, it is difficult to accurately measure the amount of total organic fluorine in water, and then, according to the current research, it is limited to qualitative research
At the same time, FAB-MS, PC-QTOF-MS, NMR, derivatization + gas chromatography, PIGE method, etc. not only have high equipment cost, but also require high professional level of operators, so they are not suitable for widespread popularization and application

Method used

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  • Method for determining total organic fluorine in water sample and aqueous solution
  • Method for determining total organic fluorine in water sample and aqueous solution
  • Method for determining total organic fluorine in water sample and aqueous solution

Examples

Experimental program
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Embodiment approach

[0053] (1) Use a suitable ultraviolet light source, which can emit vacuum ultraviolet (such as 185nm), short-wave ultraviolet (such as 254nm), and medium-wave ultraviolet (such as 300nm) any light source, and can excite sulfite ions in the aqueous solution. Produce strong reducing agent-hydrated electrons. The wavelength of the typical light source used in the present invention is 254nm, and the light intensity of a single light source is 1.6×10 16 photons s - 1 cm 3 .

[0054] (2) Use a suitable concentration of sulfite. The sulfite can be anhydrous sodium sulfite, potassium sulfite, etc. The salt is easily soluble in water and has high solubility, and the generated cations will not inhibit the reduction performance of hydrated electrons. . Typically, the present invention selects anhydrous sodium sulfite as the source of sulfite ions. The molar concentration ratio of sulfite to PFCs is 1000:1-2.0E6:1.

[0055] (3) Using a suitable initial pH of the solution, the pH of the solu...

Embodiment 1

[0063] A method for the determination of total organic fluorine in water based on ultraviolet sulfite pretreatment. The implementation process includes using an ultraviolet light source of 254nm and ultrapure water to configure 8 kinds of PFCs (54-119μg / L) with a concentration of 1.8μM. Aqueous solution, these 8 kinds of PFCs are (CF 3 ) 4 (CF) 2 C=CF 3 OC 6 H 4 SO 3 ·Na(OBS), F(CF 2 ) 4 SO 3 H(PFBS), F(CF 2 ) 8 SO 3 H(PFOS), F(CF 2 ) 7 COOH(PFOA), CF 3 (CF 2 ) 2 OCF(CF 3 )COOH·NH 3 (GenX), CF 3 (CF 2 ) 2 OCF(CF 3 )CF 2 OCF(CF 3 )COOH·NH 3 (TrA), CF 3 (CF 2 ) 2 OCF(CF 3 )CF 2 OCF(CF 3 )CF 2 OCF(CF 3 )COOH·NH 3 (TeA), F(CF 2 ) 6 (CH 2 ) 2 SO 3 ·K(6:2FTS), adjust the initial pH of the solution to 10, the molar concentration ratio of sulfite to PFCs is 1.0E4:1, and the quartz tube is plugged to isolate the air. Such as figure 1 As shown, after 3 hours of reaction, it was measured that all the fluorine in the 8 kinds of organic fluorine compounds were converted into fluorine ions. T...

Embodiment 2

[0065] A method for the determination of total organic fluorine in water based on ultraviolet sulfite pretreatment. The implementation process includes the use of ultraviolet light source of 254nm and ultrapure water to configure 10 kinds of PFCs (2.7-5.95μg / L) with a concentration of 0.09μM. The 10 kinds of PFCs are (CF 3 ) 4 (CF) 2 C=CF 3 OC 6 H- 4 SO 3 ·Na(OBS), F(CF 2 ) 4 SO 3 H(PFBS), F(CF 2 ) 8 SO 3 H(PFOS), F(CF 2 ) 7 COOH(PFOA), CF 3 (CF 2 ) 2 OCF(CF 3 )COOH·NH 3 (GenX), CF 3 (CF 2 ) 2 OCF(CF 3 )CF 2 OCF(CF 3 )COOH·NH 3 (TrA), CF 3 (CF 2 ) 2 OCF(CF 3 )CF 2 OCF(CF 3 )CF 2 OCF(CF 3 )COOH·NH 3 (TeA), F(CF 2 ) 6 (CH 2 ) 2 SO 3 ·K(6:2FTS), Cl(CF 2 ) 6 OCF 2 CF 2 SO 3 ·K(F-53B) and CF 3 O(CF 2 ) 2 O(CF 2 ) 2 OCF 2 COOH. The initial pH of the solution was adjusted to 10, the molar concentration ratio of sulfite to PFCs was 2.0E6:1, and the quartz tube was plugged to isolate the air. Such as figure 2 As shown, after 3 hours of reaction, it was measured that all the fluorine in ...

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Abstract

The invention discloses a method for determining total organic fluorine in water based on ultraviolet sulfite pretreatment, and the method comprises the following steps: performing non-selective degrading defluorination on various perfluoro / polyfluoric organic compounds (PFCs) including the organic compounds most difficult to degrade such as perfluorooctane sulfonate (PFOS) in contaminated water bodies (including drinking water, surface water and industrial wastewater, etc.) to convert organic fluorine in aqueous solution to inorganic fluoride ions, and determining the concentration of fluoride ions to obtain the amount of total organic fluorine in the water sample. The reagents and instruments used in the method are highly available, and the cost of the determination is greatly reduced compared with the current mainstream methods, and the whole process is easy to implement.

Description

Technical field [0001] The invention relates to the technical field of determination of total organic fluorine in water samples such as surface water, drinking water, industrial waste water, etc., including fluorosurfactant fire-fighting foam, liquid chromium mist inhibitor, oil extraction auxiliary, etc., and in particular to a A method for the determination of total organic fluorine in water based on UV sulfite pretreatment. Background technique [0002] Perfluoro / polyfluoroorganic compounds (PFCs) represented by perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) have been used worldwide for more than 50 years. Applications include semiconductor production, petroleum production, food packaging, and clothing , Cooking utensils and other daily necessities surface treatment, foam fire extinguishing agent additives, etc. It is estimated that at least 3000 kinds of PFCs have been produced and used. Many manufacturers usually keep secret the structure and variou...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N30/96G01N27/333G01N1/28G01N30/06
CPCG01N1/28G01N27/333G01N30/06G01N30/96G01N2030/067
Inventor 黄俊包一翔葛亮余刚
Owner TSINGHUA UNIV
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