Study On Accurate Methods To Determine The Contents Of Elements In Isooctane And Cu?In,Ga?Se₂ Film

Gasoline and Cu?In,Ga?Se₂ film solar cells are representative of traditional petroleum energy and new energy solar energy,respectively,and have an important position in China's energy structure system.The national environmental protection standard stipulates the limit of trace phosphorus in gasoline?0.2 mg/L?.Corresponding accurate measurement methods and reference materials are needed to support the quality inspection of gasoline and the implementation of corresponding standards.The content gradient of Cu,In,Ga,Se in depth profile has significant effect on the performance of solar cell such as photoelectric conversion efficiency.Therefore,it is needed to be accurate measured which can be supported by accurate measurement of main element content in Cu?In,Ga?Se₂ film.In this paper,microwave digestion combined with ICP-OES and ICP-MS were used to systematically study the influencing factors in sample preparation and analysis.The measurement method on content of phosphorus in isooctane and main elements in CIGS film was established.At the same time,a reference material of phosphorus content in isooctane was developed by using isooctane simulated light fuel.The pretreatment method of phosphorus-containing isooctane sample was established by pre-digestion and microwave digestion mode.The best pre-treatment conditions were obtained by studying and optimizing the pre-digestion conditions,sample quality,acid digestion system and microwave digestion conditions.By optimizing and exploring the measurement conditions,including correcting signal drift,suppressing matrix effects and eliminating spectral line interference,a method for accurately measuring phosphorus content in isooctane by ICP-OES and ICP-MS was established.The results show that the established measurement method can effectively eliminate the mass spectrometry interference of nitrogen oxides to ³¹P.The phosphorus content in the samples containing phosphorus isooctane was 0.4507 mg/kg and 0.4440mg/kg by ICP-OES and ICP-MS,respectively.The experimental results of the spiked recovery of phosphorus were between 98.32%and 111.41%,proving that the established sample preparation method and measurement method were accurate and reliable.A sample of a reference material of phosphorus in isooctane was prepared by using isooctane as the base and phosphate as the solute.15 bottles of standard samples were randomly selected and tested for homogeneity by Analysis of Variance.The results showed that the srandard samples had good uniformity.According to the principle of first dense and then sparse,the stability test of the standard samples under long-term 12months and short-term extreme transportation conditions?high temperature 40?and low temperature-27?,14 days?were explored by introducing straight line fitting.The phosphorus content of the standard samples was monitored for one year,and the results showed that the samples were stable.A number of laboratories were combined to determine the value of the standard sample and calculate the uncertainty.The final synthetic standard uncertainty was 0.027 mg/kg and the extended uncertainty was 0.054mg/kg.The CIGS film was completely dissolved in nitric acid by microwave digestion pretreatment method to prepare high concentration samples for ICP-OES detection.The response values of the four elements under different wavelength conditions were systematically studied.According to the high response value and linear correlation,the good judgment criterion determines the optimal wavelength of the element,and establishes the standard curve of different concentration ranges according to the different content of different elements.Finally,the content of the four elements of CIGS was 23.53%,16.63%,9.12%and 50.72%,respectively.According to the difference of elemental mass,two elements Sc and Rh were added as internal standard to detect the content of Cu,In and Ga.The standard addition method was used to remove the matrix interference.The content of Se element was measured.The atomic content of the four elements of CIGS was 24.19%,16.52%,9.44%and 49.85%by ICP-MS.The measurement results of the two detection methods were consistent and the accurate measurement method was established.The accurate determination of Cu,In,Ga and Se in the Cu?In,Ga?Se₂ film was achieved.