An On-Line Solid Phase Extraction-Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Perfluoroalkyl Acids in Drinking and Surface Waters

Figure 5

Effect of native concentration on coeluting SIL-IS peak area. (a) Injection in “early gradient” mode of 5 mL of acidified aqueous standards spiked with 100 ng/L of SIL-IS. (b) Extent of suppression of SIL-IS peak area at 100 ng/L was calculated as SIL-IS peak area of 0 ng/L native standard solution minus SIL-IS peak area of 200 ng/L native standard solution/SIL-IS peak area of 0 ng/L native standard solution X 100.

(a)

(b)