Table 1: % recoveries and their standard deviations (mean ± SD) after analysis of spiked blank samples. The precision of the method calculated as % RSD for four measurements of each sample.

⁢Mean recoveries
7 ng g−1% RSD25 ng g−1RSD40 ng g−1RSD70 ng g−1RSD

α-HCH90.87 ± 6.266.8991.46 ± 8.068.8292.07 ± 10.7211.6494.47 ± 3.163.28
HCB83.79 ± 9.0110.7681.54 ± 10.4812.8686.46 ± 3.954.5689.59 ± 10.2112.11
β-HCH76.62 ± 8.0510.5081.90 ± 9.5711.6987.03 ± 11.2912.97113.92 ± 15.4412.82
Aldrin85.36 ± 10.9612.8491.46 ± 5.465.9791.56 ± 4.484.8995.35 ± 6.326.14
Heptachlor 81.82 ± 3.764.6099.28 ± 13.3313.4398.70 ± 5.815.89101.77 ± 4.724.69
o,p-DDE74.76 ± 6.508.6988.78 ± 9.0110.15101.94 ± 5.965.85102.03 ± 5.745.52
α-Endosulfan75.97 ± 11.9615.74103.21 ± 4.714.56105.01 ± 11.4310.89107.36 ± 6.666.55
p,p-DDE75.80 ± 8.7811.2497.98 ± 12.7613.0298.39 ± 3.373.43105.96 ± 2.562.41
Dieldrin75.04 ± 8.4111.5893.01 ± 9.8810.6397.60 ± 9.8810.12107.25 ± 11.9011.68
Endrin93.43 ± 5.275.6495.68 ± 8.228.59106.34 ± 5.385.06107.07 ± 5.565.53
β-Endosulfan69.58 ± 7.2010.3595.76 ± 10.0410.49110.59 ± 5.584.86112.74 ± 1.341.19
p,p-DDD82.78 ± 8.8710.7298.45 ± 5.265.3599.44 ± 8.068.11102.56 ± 8.238.02
o,p-DDT103.71 ± 8.628.31100.40 ± 11.2711.23101.04 ± 6.556.48102.95 ± 5.544.90
p,p-DDT76.39 ± 13.7317.9789.66 ± 7.548.4198.84 ± 5.575.6498.36 ± 12.8213.03