石英滤光镜中NI含量检测方案(ICP-AES)

ICP ATOMIC EMISSION SPECTROSCOPY 2HORIBAExplore the futureAutomotive Test Systems IProcess & Environmental11Medical 1SemiconductorlScientific Analysis of Quartz Filters Agnes Cosnier HORIBA Scientific Longjumeau， France Keywords： environment， air samples 1 Introduction Quartz filters are used to monitor air contamina-tion； they are often placed in work areas wherepotential specific contamination can occur. Theanalysis of impurities in quartz filters wasundertaken after digestion with HF and HNO3.The ULTIMA was used because of its high sen-sitivity. 2 Principle 2.1 Technique used The elemental analysis of solutions was under-taken by Inductively Coupled Plasma AtomicEmission Spectrometry (ICP-AES). The sampleis nebulized then transferred to an argon plas-ma. It is decomposed， atomized and ionizedwhereby the atoms and ions are excited. Wemeasure the intensity of the light emitted whenthe atoms or ions return to lower levels of ener-gy.Each element emits light at characteristicwavelengths and these lines can be used forquantitative analysis after a calibration. 2.2 Wavelength choice The choice of the wavelength in a given matrixcan be made using the “profile" function， or byusing Win-IMAGE， which is rapid semi-quantita-tive analysis mode using multiple wavelengths.The principle is the same in either case： recordthe scans of analytes at low concentration， andof the matrix.By superimposing the spectra， wesee possible interferences. 3 Sample Preparation Samples were digested as follows： One quartz filter was placed in a 25 mL volu-metric flask with 4 mL of 40% Hydrofluoric acid(HF) and 2 mL of 69% Nitric acid (HNO?). Any heating should be restricted to 55℃ toavoid the loss of Si. However， if Si is notrequired， heating to higher temperatures willensure all Si is lost and reduces the dissolvedsolids content of the solutions. 4 Instrument specification The work was done on a ULTIMA.The specifica-tions of this instrument are listed below inTables 1 and 2. Table 1： Specification of spectrometer Parameters Specifications Mounting Czerny-Turner Focal length 1 m Number of grating 2 Grating 1 number of grooves 4 320 gr/mm Grating 2 number of grooves 2 400 gr/mm Thermoregulation Yes Variable resolution Yes Nitrogen purge Yes Table 2： Specification of RF Generator Parameters Specifications Observation Radial Frequency 40.68 MHz Control of gas flowrate By computer Control of pump flow By computer Cooling Air 4 Operating conditions The operating conditions are listed in Table 3below. Table 3： Operating conditions Parameter Condition RF Generator power 1100 W Plasma gas flowrate 13 L/min Auxiliary gas flowrate 0 L/min Sheath gas flowrate 0.2 L/min Nebulizer flowrate 2.8 bars Sample uptake 1 mL/min Type of nebulizer Tangential Type of spray chamber Cyclonic in inert material Argon humidifier No Injector tube diameter 3.0 mm 5 Standards The standards were prepared in the same acidmixture as the samples. The concentrations of thestandards， in mg/L， are given in the followingtable： Table 4： Standard concentration Be 0 0.005 0.020 0.050 Cd 0 0.5 1 2 Cr 0 1 8 16 Ni 0 2 16 32 Pb 0 0.5 2 4 6 Wavelength selection and analyti-cal conditions Mode of calculation： Mode maximum， ideal fortraces. Five points measured， one used for calcu-lation. Entrance slit： 20 umExit slit： 15 pmIntegration time： 4 s and 2.5 s for background cor-rection. 7 Accuracy Table 5 gives the concentration in pg/l obtainedon three samples compared to results expected. Table 5： Results for accuracy Obtained/Expected Obtained/Expected Be 0.39 0.40 44.5 48 0.61 0.60 Cd 11.9 12 157 160 1972 2000 Cr 121 120 1857 2000 182.5 200 Ni 192 240 23732 24000 1885 2000 Pb 42.8 40 3593 3600 362 360 8 Conclusion Forthe analysis of low levels， it is important to getaccurate "blank" values for environmental air sam-ples. For environmental air sampling every batchof silica filters must be analyzed. The results showthe methodology used and the instrumentationperform this task very well. France： HORIBA Jobin Yvon S.A.S.， 16-18 rue du Canal， 91165 Longjumeau Cedex - Tel： +33 (0)1 64 54 13 00-Fax： +33 (0)1 69 09 07 21-Email： info-sci.fr@horiba.com USA： HORIBA Jobin Yvon Inc.， 3880 Park Avenue， Edison， NJ 08820-3012. Toll-free： +1-866-jobinyvon- Tel：+1-732-494-8660- Fax： +1-732-549-5125 Email： info-sci.us@horiba.com Japan： HORIBA Ltd.， Scientific Instruments Sales Dept.， Alte-Building Higashi-Kanda， 1-7-8 Higashi-Kanda， Chiyoda-ku， 101-0031 Tokyo- Tel： +81 (0)3 3861 8231 Fax： +81 (0)3 3861 8259-Email： info-sci.jp@horiba.comGermany： HORIBA Jobin Yvon GmbH， Hauptstrasse 1， 82008 Unterhaching- Tel： +49 (0)89 46 23 17-0- Fax： +49 (0)89 46 23 17-99-Email： info-sci.de@horiba.com Italy： HORIBA Jobin Yvon Srl， Via Cesare Pavese 35/AB， 20090 Opera (Milano)-Tel： +39 0257 603050-Fax： +39 0 2 57 60 08 76-Email： info-sci.it@horiba.com UK： HORIBA Jobin Yvon Ltd， 2 Dalston Gardens， Stanmore， Middlesex HA7 1BQ-Tel：+44 (0)20 8204 8142-Fax： +44 (0)20 8204 6142-Email： info-sci.uk@horiba.com China： HORIBA Jobin Yvon SAS， Room 1801， Capital Tower No.6， Jianguomenwai Av.， Chaoyang District， Beijing 100022 -Tel： +86 (0)10 8567 9966-Fax： +86 (0)10 8567 9066 Email： info-sci.cn@horiba.com Other Countries： Tel： +33 (0)1 64 54 13 00-Email： info.sci@horiba.com For the analysis of low levels, it is important to get accurate "blank" values for environmental air samples. For environmental air sampling every batch of silica filters must be analyzed. The results show the methodology used and the instrumentation perform this task very well.