血浆中硒元素的检测

Aurora Instruments Ltd. Aurora Instruments Ltd.1001 East Pender St.， Vancouver B.C.Web site： http：//www.aurora-instr.com Application Notice #AA-3 Application Procedure for the Determination of Selenium in Blood Plasma Introduction： Selenium is extremely susceptible to sublimating out of the sample solution at relatively lowtemperatures due to its low melting point. Therefore， selenium is a very difficult element toanalyze in atmospheric conditions.i. To accurately determine the selenium concentration， caremust be taken in all steps of sample preparation to prevent sample volatilization from occurring. Usually， selenium volatilization is eliminated by using a matrix modifier such as nickel (60-500ppm) which forms a less volatile nickel -selenium alloy， stable up to about 1300°C. Whenthe sample is ashed most organic materials will be destroyed while the nickel-selenium alloyremains stable. Consequently， at 1300°℃ when atomization of the selenium occurs， backgroundabsorbance will be minimized causing the Se signal to be enhanced. Sample Preparation Procedure： 1. Thaw the plasma samples at room temperature for 15-20 minutes. 2. Homogenize the samples byslowly vortexing. 3. Dilute the plasma with deionized water in a 1：1 ratio directly a into microplate. (160pLplasma+ 160pL water is a good volume) 4. Mix to homogenize for 2-3 minutes with a microplate mixer (Remark： the sample will beinjected directly without digestion). 5. Plasma Controls should be prepared identically as above. Standard Preparation： The standards for the calibration curve are to be made up from a known concentration of UtakHigh Control # 8550 (301ug/L Se) Standard No. Utak High ControlVolume (uL) Water volume (uL) Concentration (ppb) 1 16 286 20 2 40 262 50 3 80 222 100 4 120 182 150 UTAK Laboratories， Inc.， 25020 Avenue. Tibbitts， Valencia， CA 91355 Tel： (800) 235-3442 Fax： (805) 294-9272 cont. on back Operating Conditions： Instrumentation： Aurora Al 1100/2100 GFAAS Parameter of settings： Injection Volume-20 pL Modifier added： 10 uL 60 ppm Ni solution (made of NiCl26H2O) in 0.05 M Hcl) AURORA INSTRUMENTS AI 1100/2100 Method Name plasma-se Element Name Se Instrument Mode Absorbance Display Mode Corrected Manual Band Pass 0.7nm Lamp 1 Current 8.0 mA Lamp 2 Current 0.0 mA Wavelength 196.00nm PMT Voltage 481.0V Preheat Steps 0 Cooling Time 60s Inject Speed 5 Furnace Profile Steps 9 Step finaltemp ramptime holdtime GasFlow PlasmaON CollectData Integrate 1 50 0.00 2.00 1.00 Off Off Off 2 160 40.00 1.00 1.00 Off Off Off 3 300 6.00 2.00 1.00 Off Off Off 4 900 2.00 15.00 1.50 Off Off Off 5 1200 1.00 6.00 1.50 Off Off Off 6 1300 0.00 1.00 1.50 Off On Off 7 2100 0.00 1.00 0.50 Off On On 8 80 0.00 1.00 1.50 Off On Off 9 50 0.00 15.00 1.50 Off Off Off Note Normal Concentration of Selenium in Blood Plasma is expected to be in the range of 30-200ppb Tel： (604) 215-8700：FFax：(604)215-9700 E-mail： aurora@intergate.bc.ca