Determination of lead in rice based on nafion and multiwalled carbon nanotube modified glass carbon electrode with techniques
A new method based on Nafion and multiwalled carbon nanotube(MWCNT) modified glass carbon electrode(GCE) has been established for rapid detection of lead in rice sample.The electrochemical behavior of lead on the modified GCE was investigated and the sensor signal was recorded using stripping voltammetry.The results showed that under the optimized conditions including 0.1 mol/L NaAc-HAc usded as surporting buffer(pH4.0),-0.6 V of accumulating potential,180 s of accumulating time,an excellent linear sensor response of stripping peak current was displayed to the concentration of lead ion in the range from 0.01 mg/L to 1 mg/L with a detecting limit of 5 μg/L,showing favorable sensitivity to meet the National Standard for lead quantification in rice.In addition,this methods showed the advantages of short assay time(within five minutes),good acuracy,satisfactory efficiency and stability for determination of lead in large amount of samples.Consequently,this technique provided primitive experimental model for fast detection of heavy metals on the sites.