Table 3 Precision and accuracy of paraben analysis by MALDI-TOF MS.

From: A derivatization-enhanced detection strategy in mass spectrometry: analysis of 4-hydroxybenzoates and their metabolites after keratinocytes are exposed to UV radiation

Concentration known (μg/mL)

Intra-day (n = 5) a

Inter-day (n = 5) b

Concentration found (μg/mL)

RSD c (%)

RE d (%)

Concentration found (μg/mL)

RSD c (%)

RE d (%)

Methyl paraben

 0.25

0.25 ± 0.01

4.00

0

0.25 ± 0.01

4.00

0

 4.00

3.97 ± 0.09

2.27

−0.75

3.85 ± 0.04

1.04

−3.75

 9.00

9.04 ± 0.12

1.33

0.44

8.96 ± 0.03

0.33

−0.44

Ethyl paraben

 0.25

0.23 ± 0.01

4.35

−8.00

0.24 ± 0.02

8.33

−4.00

 4.00

3.82 ± 0.12

3.14

−4.50

3.87 ± 0.29

7.49

−3.25

 9.00

8.92 ± 0.09

1.01

−0.89

8.90 ± 0.54

6.07

−1.11

Propyl paraben

 0.25

0.23 ± 0.01

4.35

−8.00

0.24 ± 0.02

8.33

−4.00

 4.00

3.87 ± 0.16

4.13

−3.25

3.90 ± 0.23

5.90

−2.50

 9.00

8.89 ± 0.24

2.70

−1.22

8.94 ± 0.45

5.03

−0.67

Butyl paraben

 0.25

0.24 ± 0.01

4.17

−4.00

0.23 ± 0.01

4.35

−8.00

 4.00

3.86 ± 0.13

3.37

−3.50

3.95 ± 0.19

4.81

−1.25

 9.00

8.95 ± 0.14

1.56

−0.56

9.27 ± 0.56

6.04

3.00

  1. aIntra-day assay variance was calculated from the triplicate assay values on a single day.
  2. bInter-day assay variance was calculated from the triplicate assay values on five different days.
  3. cRSD (%) = (SD/mean) x 100.
  4. dRE (%) = [(Concentration found-Concentration known)/Concentration known] × 100.
Back to article page