Study of tau‐fluvalinate persistence in honey

Abstract

The persistence of the acaricide tau-fluvalinate with time and the factors that can affect its degradation in honey were investigated. Two honey types of extreme pH values (3.85 and 5.40) were spiked with tau-fluvalinate at two levels (50 and 200 micrograms kg-1) and incubated at 35 degrees C. Samples were analyzed in duplicate at various time intervals for up to 248 days. A simple, rapid and accurate method for the determination of tau-fluvalinate residues in honey is proposed. Tau-fluvalinate extraction and sample cleanup was carried out using C8 SPE cartridges with dichloromethane as the elution solvent. Analysis of samples was accomplished using gas chromatography with electron-capture detection (GC-ECD). The overall recovery of the method was 90.25 (+/- 0.85)% and the limit of determination 1 microgram kg-1. The results showed that tau-fluvalinate stays stable in honey for more than 8 months, even at 35 degrees C. The effect of higher temperatures, similar to those used for honey packing, on tau-fluvalinate persistence in honey was also studied. Honey samples fortified with 20 and 200 micrograms kg-1 tau-fluvalinate were subjected to heat treatment similar to that in the honey blending and packing process. No degradation of tau-fluvalinate due to the heat treatment was recorded. This long persistence increases the risk of honey contamination due to repeated and/or extended tau-fluvalinate applications.

tau‐Fluvalinate and other pesticide residues in honey bees before overwintering

“…However, varroacides can be applied at high doses, and toxic effects against bees, including effects on their behavior, have been recorded. Another important issue with varroacides is the potential unwanted contamination of colony products such as wax, honey, royal jelly, and propolis . However, investigation of the tau ‐fluvalinate concentration is more common in bee products than in bees …”

“…Another important issue with varroacides is the potential unwanted contamination of colony products such as wax, honey, royal jelly, and propolis. [14][15][16][17][18][19] However, investigation of the tau-fluvalinate concentration is more common in bee products than in bees. 12 tau-Fluvalinate is one of the most important active compounds used to control Varroa; however, extensive and repeated use of tau-fluvalinate contributes to the selection of resistant mite populations and hampers the efficacy of the varroacide.…”

Predicting pesticide fate in the hive (part 1): experimentally determined τ-fluvalinate residues in bees, honey and wax

“…Residues of fat-soluble and stable pesticides have been found in surveys in many countries: Greece (Thrasyvoulou and Pappas 1988), Italy (Lodesani et al 1992(Lodesani et al , 2008Russo and Neri 2002), Switzerland (Bogdanov et al 1998(Bogdanov et al , 2003, France (Martel et al 2007;Chauzat and Faucon 2007), Germany (Wallner 1999), Spain (FernandezMuiño et al 1995(FernandezMuiño et al , 1997García et al 1996;Jiménez et al 2005), Portugal (Rial-Otero et al 2007), North America (Nasr and Wallner 2003;Mullin et al 2010) and Saudi Arabia (Kamel and Al-Ghamdi 2006). Experiments designed to assess the persistence, fate and metabolism of various pesticide compounds have been performed over periods of up to 2 years using experimental hives (van Buren et al 1992;Bogdanov and Kilchenmann 1995;Fries et al 1998;Tsigouri et al 2001Tsigouri et al , 2004Waliszewski et al 2003;Tremolada et al 2004;Martel et al 2007). …”

Pesticide Residues in Bee Products

“…The bound substances are eluted with the passage of an appropriate organic solvent. In the case of honey acetone , dichloromethane (Jimenez et al, 1998), ethyl acetate (Tsigouri et al, 2001), hexane (Gomis et al, 1996), methanol , a mixture of hexane-ethyl acetate (Tsigouri et al, 2001) have been occasionally used. With regard to the types of substrates used occasionally, the reverse phase C 18 was the most appropriate and chosen by most researchers for the extraction of insecticides, acaricides, herbicides, fungicides and other pesticides Bernal et al, 2000;Korta et al, 2001).…”

“…With regard to the types of substrates used occasionally, the reverse phase C 18 was the most appropriate and chosen by most researchers for the extraction of insecticides, acaricides, herbicides, fungicides and other pesticides Bernal et al, 2000;Korta et al, 2001). Also microcolumn with Florisil gave good results in trials for determination of pyrethroid, OCP and OPP residues (Jimenez et al, 1998a) and C 8 in the determination of tau fluvalinate (Tsigouri et al, 2001). The pH adjustment proved particularly important for the good recovery of some active substances.…”