ABSTRACT
Volume concentration determination for atmospheric krypton and xenon is very important for krypton-85 and radioactive xenon isotopes monitoring. An injection setup integrated adjustable quantity sample injection and quantitative dilution function was designed. The effects of EI source parameters on the sensitivity of MS detector were studied. The optimized values were as following: ionization energy of 70 eV, emission current of 40 mA, cathode voltage of 27 mV, focus voltage of 85 mV and lens compensation of 20 V, respectively. A GC-MS method for the determination of krypton and xenon in atmosphere without of sample pretreatment was developed. The minimal detected concentrations for krypton and xenon were 3. 3×10-8(V/V) and 2. 6×10-9(V/V). Moreover, the krypton and xenon concentrations in the ground level air around our laboratory were measured with the results of 1 . 1 × 10-6 ( V/V ) and 9 . 3 × 10-8 ( V/V ) . The related combined standard uncertainties for krypton and xenon results were 2. 38% and 3. 15%, respectively.
ABSTRACT
Objective To develop a gas chromatography-mass spectrometric method(GC/MS) for simultaneous determination of environmental estrogens including 4-nonylphenol,bishphenol A,diethylstilbestrol and 17?-ethinylestradiol and endogenic estrogens including 17?-estradiol,17?-estradiol,estriol and estrone in mutton. Methods Mutton samples were extracted using a mixture of acetonitrile-ethyl acetate(3∶2,V/V) and cleaned up by florisil cartridge. Derived with pentafluoropropionic anhydride(PFPA) ,the derivatives were determined by GC-MS. Results The linear range of determination was 0.2-5.0 ?g/kg. The intraday relative standard deviations of the peak area were 1.25%—5.85% and the detection limits ranged from 0.024 to 1.40 ?g/kg,and the rates of recovery ranged from 71.5%—111.0% except for 17?-ethinylestradiol( 55.4%) . Conclusion This method is simple,rapid,accurate and applicable to the determination of trace environmental estrogens in mutton