[Mercury speciation in aquatic products analyzed by liquid chromatography cold vapor atomic fluorescence spectrometry].

OBJECTIVE

To establish a method for the detection of mercury species in aquatic products by liquid chromatography online coupled with cold vapor atomic fluorescence spectrometry(LC-CV-AFS) and to participate in the international proficiency tests to verify the method.

METHODS

Mercury species were extracted from aquatic samples by using ultrasonication-assisted acid extraction, separated by reversed phase liquid chromatography, decomposed into inorganic mercury ion with on line UV digestion system, and then determined by cold vapor atomic fluorescence spectrometry.

RESULTS

Methylmercury, ethylmercury and inorganic mercury were baseline separated within 20 minutes. The linear range was 1-20 microg/L for the three species and the correlation coefficient r > or = 0.999. The detection limits for methylmercury, ethylmercury and inorganic mercury were 1 microg/kg, 2 microg/kg and 1 microg/kg respectively. The recovery of samples for three spiked levels (10, 50 and 500 microg/kg) was in the range of 89%-106%. The relative standard deviations (RSDs) were less than 10%. The determined methylmercury contents of certified reference materials (CRMs) were agreed well with the certified values. The results of determined methylmercury values were satisfied (Z <2) in two international proficiency tests, i.e., Food Analysis Performance Assessment Scheme (FAPAS, UK)-07115 test and International Atomic Energy Agency (IAEA)-452 test.

CONCLUSION

The LC-CV-AFS method is simple, sensitive and accurate and could meet the demand for mercury speciation in aquatic products.