ABSTRACT
The environmental organic pollutant of di-2-ethylhexy phthalate ( DEHP ) was analyzed by extractive electrospray ionization mass spectrometry ( EESI-MS ). Effect of some important experimental conditions were investigated systematically, including the electrospray voltage, temperature of ion-transport tube, sample injection rate and extractant composition. Under the optimal conditions, a method for rapid detection of DEHP in water sample was established. DEHP levels in different samples with complex matrixes were measured, including landfill leachate, urban sewage and lake water. The results showed that DEHP in water samples could be ionized by EESI source and obtained the molecule ion (m/ z 391. 28) at the positive detection mode, and then CID experiment were performed to obtain the secondary fragment ions m/ z 279. 26, 167. 12 and 149. 11. The intensity of characteristic peak m/ z 149. 11 possessed a good linearity with the concentration of DEHP in the range of 5-1000 μg / L with the correlation coefficient of R2 = 0. 9991, and the detection limit (LOD) of 0. 21 μg / L. The recoveries of DEHP at three spiked levels (8, 80, 400 μg / L) were 96. 2％ - 111. 2％ , with RSDs of 5. 6％ - 11. 8％ . With the developed EESI-MS method, the concentrations of DEHP in landfill leachate, urban sewage and Yan lake water were 556. 5, 275. 3 and 37. 8 μg / L, respectively. The EESI-MS method possessed many advantages such as no requirement of sample pretreatment, fast analysis speed ( about 3 min per sample), simple operation and high sensitivity, thus providing a new mass spectrometric method for rapid detection of phthalate esters.
ABSTRACT
Objective To establish a continuous flow analytical method for determination of potassium in environmental water sample.Methods The concentration of patassium in environmental water sample was determined by ALLIANCE auto-matic analyzer,and its data were compared with the data obtained from atomic absorption spectrophotometry.Results The de-tection limit of this method was0.5?g /ml.The method revealed linear relationship at the potassium concentrations of5-1000?g /ml.The recovery rate of standard addition method ranged from to97%to102%.The relative standard deviations were0.82%-1.23%.Conclusion The contents of potassium in environmental water samples could be accurately and rapidly deter-mined by continuous flow analysis.