Research Article

Quantitative Measurement of Plasma Free Metanephrines by a Simple and Cost-Effective Microextraction Packed Sorbent with Porous Graphitic Carbon and Liquid Chromatography-Tandem Mass Spectrometry

Figure 2

Influence of different parameters on MEPS efficiency: (a) effect of the number of extraction cycles, (b) effect of the elution solution, and (c) carryover of MEPS.
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(b)
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