用SPEX冷冻研磨机研磨人类牙齿而后用悬浮液进样石墨炉原

A simple method is proposed for copper, lead and manganese determination in deciduous teeth by graphite
furnace atomic absorption spectrometry (GFAAS) using slurry samp领 introduction and cryogenic sample
preparation. Teeth samples were ground in a cryogenic mill in two steps: pre-coo领 (5 min) and cryogenic
grinding (2 min) in liquid nitrogen. After grinding, 90% of the sample particles were lower than 150 mm. The
minimum mass necessary for slurry preparation as an indicator of sub-sample homogeneity was evaluated by
weighting masses between 5 and 20 mg directly in autosampler cups, followed by addition of 1 mL of a
solution containing 0.04% Triton1 X-100 and 0.2% v/v HNO3. Samples (20 mL) were sonicated during 20 s,
before delivering into a WRh coated platform. Detection limits based on integrated absorbance were
34.0 ng g21 Pb, 7.4 ng g21 Mn and 18.0 ng g21 Cu for 2% m/v slurries. WRh permanent modifier permitted
calibration against aqueous standards. The Certified Reference Material (H-5 animal bone) from the
International Agency of Atomic Energy (IAEA) was analyzed to determine lead for method validation. For
copper, lead and manganese, 12 human teeth samples were analyzed using the proposed method with
calibration against aqueous solution and using a comparative Pd/Mg method with the same digested samples,
and standard addition calibration, with no statistical difference at 95% level on applying the t-test. SPEX6770 全自动冷冻研磨机 SPEX6870 全自动冷冻研磨机 SPEX6970EFM 冷冻研磨机