The calibration curves were generated in the range of 0.5
–
100 ng/g using a least-squares linear regression analysis. The correlation
coefficients of seven n-nitrosamines were above 0.99 as
shown in Table 4. MDLs were measured by analyzing seven replicate
samples spiked with n-nitrosamine standards per 5 g of the
control samples. The value was de
fined as the lowest concentration,
which provides a greater than 99% confidence when the
procedure was used where the measured concentration was distinguishable
from the method blank result. MDLs of seven n-nitrosamines
in the cosmetic control samples range from 0.46 to
36.54 ng/g which were within the limit of the Directive 76/768/
EEC established by the European Union [19]. The average recoveries
are 79% within 20% RSD at 50 ng/g. The proposed method