From:  Occurrence of alkylphenols in drinking water samples by solid phase extraction gas chromatography-mass detection analysis

 Recovery values (%) and intra-day precision values, expressed as RSD (%), obtained for different concentrations of spiked waters analyzed by the proposed methodology.

Concentration (ng/L)Recovery (% ± s, n = 9) [RSD, %]
Analyte4-OP4-tOP4-NP
5096.5 ± 0.2 [0.2]98.2 ± 0.7 [0.7]88.2 ± 1.3 [1.5]
25093.3 ± 0.4 [0.4]92.0 ± 0.9 [1.0]91.7 ± 0.2 [0.2]
1,00088.6 ± 0.5 [0.6]99.2 ± 0.6 [0.6]89.5 ± 0.8 [0.9]

4-OP: 4-octylphenol; 4-NP: 4-nonylphenol; 4-tOP: 4-tert-octylphenol.