Dissipation of malathion and fluvalinate residues from honey

SUMMARY

A gas chromatographic method was developed and used to analyse the rate of degradation of malathion and fluvalinate in honey under both hive and storage conditions. The pesticides were applied inside hives as dust preparations (malathion) or sprays (fluvalinate), as would be done to control varroa disease. Samples of honey spiked with the pesticides were also analysed. Malathion degraded rather slowly under hive or storage conditions and its residues reached levels below the detectable limit of the developed method (0.5 ppb) 13 weeks after application. The degradation rate of fluvalinate, under similar conditions, was slower and its residues in honey fell to the detectable limit of the developed method (5 ppb) 28 weeks after treatment. It is concluded that when the above chemicals are applied inside the hive as described, the time intervals between the last application and the honey harvest ought to be about 13 weeks for malathion and 28 weeks for fluvalinate in order to minimize their residues in honey.

Keywords:

• honey
• malathion
• fluvalinate
• pesticide residues
• degradation
• storage
• gas chromatography