The Detection Of Rubidium And Organic Matter In The Sichuan Basin Underground Brine

In this paper, the organic compounds in brine foam in western Sichuan provincecity qionglai was analyzed. Analyzed the types of organic compounds and identifiedsome organic compounds’ contents. Then took the bring foam into filtration device,separated into solid foam and clear solution,called the clear solution bubble water.Then bubble water was extracted by organic solvent, and concentrateit,determined with GC-MS method;foam solid was extracted by soxhlet with organicsolvents and determined by GC-MS. To optimize the foam water pre-treatmentconditions: define the optimal dilution of the foamed cement ratio is1.5:1;the bestratio of mixed with foam water and extractant dichloromethane, chloroform, hexaneand mixed extractant respectively is4:1,4:1,2:1and3:1; optimize to select theextraction solvent and extraction method after10kinds of different methods of test byuse the actual brine;then obtain the organic sample,determined by GC-MS afterconcentrated,get the organic matter type and content of the brine according to analysisof GC-MS peak diagram and mass spectrum.Test showed that: The foam is rich in n-alkanes，from C11to C30，and The mainpeak showed a normal distribution mainly from C12to C15; organic matter in foamwater is relatively few, including alcohols, ketones, aromatic hydrocarbons. Theexperiment compared several different extraction agents and mixed extractionmethods, and ultimately learned that the chloroform and hexane had strongerextraction ability; Mixed extractant showed unexpected results,may because of theeffect of each other between the two different polarities of the extractant,lead to Poorextraction efficiency but except the method of step-by-step extraction. Detectedobjects in the brine foam mainly is n-alkanes, under the supernatant mainly detectedobjects is aromatic hydrocarbons, alcohols,that is to say that organic species in thesupernatant and foam is been separated. N-alkanes is the existence of solid-like, easy to be adsorbed by the foam, it has a very low solubility in the brine, so it exist in thefoam solid; aromatic hydrocarbons, alcohols, etc, is the existence of liquid, containinghydrophilic groups,has a greater solubility in the brine, so it exist in the supernatant.In the paper,we did some research about determination of rubidium in better atpingluo fourth-well by inductively coupled plasma-optic emission spectrometry. In theICP-OES determination of microamounts of rubidium in bittern, interferences ofco-existing ions, including Li~+, Na~+, K~+,Ca2~+, Mg2~+,and H~+were tested, and on thebasis of the results obtained, the analytical conditions for ICP-OES determination ofrubidium given in literature were modified.Used different algorithms (peak area and peak height) to determine instrumentprecision and detection limits, using standard addition recycled experiments to verifythe accuracy and reproducibility of the method. To make use of different systemelements to do the interference experiment, which give some guidance on theconditions of determinate actual brine. Consider content gradient that may occur inthe actual brine, to do the dilution experiments to address the concerns about theaccuracy of the measured concentration large span in the process.It was found that when definite amounts of the co-existing ions which were makesure very close to the amounts present in the sample were added to the testingsolutions in the preparation of standard curve of rubidium, their interferences wereeliminated by compensation or other design. Thus, rubidium in bittern wasdetermined directly without any pretreatment. The proposed method was applied todetermine rubidium in testing known bittern samples, giving results in consistencywith the known values.The relative standard deviations were less than5%and therecoveries of most elements were in the range of99%-103%. The method isreproducible, accurate, convenient, simple preparation and so on.In this paper, according to the characteristics of brine in Sichuan,we have donein-depth research on the methods of detect organic and rubidium by GC-MS andICP-OES, to establish a complete set of practical analytical methods,which play amore important role in the development and utilization of brine.