scholarly journals Penetration of methyl bromide, sulfuryl fluoride, ethanedinitrile and phosphine into timber blocks and the sorption rate of the fumigants

2011 ◽  
Vol 47 (2) ◽  
pp. 63-68 ◽  
Author(s):  
YongLin Ren ◽  
ByungHo Lee ◽  
Benjamin Padovan
Keyword(s):  
Methyl Bromide ◽  
Sorption Rate ◽  
Sulfuryl Fluoride

Comparison of the Efficacy and Phytotoxicity of Phosphine and Ethyl Formate for Controlling Pseudococcus longispinus (Hemiptera: Pseudococcidae) and Pseudococcus orchidicola on Imported Foliage Nursery Plants

2019 ◽  
Vol 112 (5) ◽  
pp. 2149-2156 ◽  
Author(s):  
Yejin Kyung ◽  
Hyun Kyung Kim ◽  
Sung Woo Cho ◽  
Bong-Su Kim ◽  
Jeong-Oh Yang ◽  
...  
Keyword(s):  
Plant Species ◽  
Methyl Bromide ◽  
Reduction Rate ◽  
Ethyl Formate ◽  
Sorption Rate ◽  
Pseudococcus Longispinus ◽  
High Sorption ◽  
Fumigation Chamber ◽  
Nursery Plant ◽  
Schefflera Arboricola

Abstract The fumigation activity of phosphine (PH3) and ethyl formate (EF) and their phytotoxicity to 13 imported foliage nursery plant species were evaluated. The lethal concentration and time (LCT99) values of the PH3 indicated that the susceptibility of the nymphs (3.95 and <0.45 mg·h/liter, respectively) was higher than that of the adults (5.29 and 3.66 mg·h/liter, respectively) of two mealybugs [Pseudococcus longispinus (Targioni-Tozzetti) and P. orchidicola Takahashi]. The highest concentration reduction rate of PH3 and EF on the 13 foliage nursery plants in the 12-liter desiccator was 41.5% for Heteropanax fragrans and 71.7% for Schefflera arboricola, respectively, which indicates that PH3 has a lower sorption rate than EF. The phytotoxicities of PH3-treated foliage nursery plants did not significantly differ from those of the nontreated plants, but EF caused phytotoxicity in 11 foliage nursery plants a week after treatment. When the exposure time of PH3 increased to 24 h, the adults and nymphs of both mealybug species showed 100% mortality in the 0.5 m3 fumigation chamber. In the 10 m3 fumigation container used in the field, there was 100% mortality of both mealybugs after treatment with 2 g/m3 PH3 for 24 h at 16°C. These results indicate that EF is not a suitable mealybug fumigant due to its high sorption and phytotoxicity to foliage nursery plants, despite fumigation activity against the two species. However, PH3 seems to be suitable for mealybug fumigation in foliage nursery plants and can be used as a substitute for methyl bromide.

Survival of the Oak Wilt Fungus in Logs Fumigated with Sulfuryl Fluoride and Methyl Bromide

2019 ◽  
Vol 69 (1) ◽  
pp. 87-95
Author(s):  
Anna Yang ◽  
Kendhl Seabright ◽  
Jennifer Juzwik ◽  
Scott W. Myers ◽  
Adam Taylor
Keyword(s):  
Methyl Bromide ◽  
Slow Variable ◽  
Current Treatment ◽  
Treatment Schedule ◽  
Level Control ◽  
Oak Wilt ◽  
Sulfuryl Fluoride ◽  
Concentration Time ◽  
Pathogen Colonization ◽  
And Diffusion

Abstract Methyl bromide (MB) fumigation of oak (Quercus sp.) logs destined for export is required to mitigate risks associated with movement of the oak wilt fungus, Bretziella fagacearum. Alternative fumigants with efficacy against B. fagacearum are needed because of MB's ozone-depleting properties. Fumigation with sulfuryl fluoride (SF) is considered a promising substitute. Logs (1.8 m long) were obtained from Quercus trees (18.3 to 29.2 cm diameter at breast height) that were naturally infested (NI) or artificially inoculated (AI) with B. fagacearum to compare pathogen colonization and survival following fumigation with SF and MB. The logs were fumigated with SF for 72 hours with 240, 280, and 320 g/m3 or 96 hours with 128 and 240 g/m3. MB fumigations were conducted using the current treatment schedule for oak logs destined for export (240 g/m3 for 72 h). Frequencies of successful pathogen isolation before treatment were higher for AI logs than for NI logs based on isolation rates from sapwood chips. Treatments greatly reduced frequencies of viable pathogen presence, but no treatment was successful in eradicating the pathogen. Experiments were conducted on blocks (10.2 by 10.2 by 11.4 cm3) obtained from Quercus trees to investigate simulated penetration and diffusion of SF and MB into oak logs. Slow, variable fumigant diffusion never reached concentration–time products lethal to B. fagacearum. Based on these results, reliance on SF alone as a quarantine measure may require higher concentration × time products to achieve quarantine level control of the oak wilt fungus in logs.

Optimization and Validation of HS-SPME-GCMS Method for Determination of Multifumigant Residues in Grain, Oilseeds, Nuts, and Dry Fruit

2019 ◽  
Vol 102 (6) ◽  
pp. 1877-1883 ◽  
Author(s):  
Xin Du ◽  
Wenjuan Zhang ◽  
Bo Liu ◽  
Tao Liu ◽  
Yu Xiao ◽  
...  
Keyword(s):  
Ethylene Oxide ◽  
Propylene Oxide ◽  
Methyl Bromide ◽  
Ethyl Formate ◽  
Ethyl Bromide ◽  
Gas Chromatograph ◽  
Sulfuryl Fluoride ◽  
Dried Fruit ◽  
Food Matrices

Abstract Background: Fumigants are approved in many countries and used to treat food, feed, and seed. The amount of residue that remains in fumigated materials is measured and reported. Objective: The optimization and validation of a high-sensitivity headspace solid-phase microextraction gas chromatograph mass spectrometer (HS-SPME-GCMS) method for determination of eight fumigant residues—phosphine, methyl bromide, cyanogen, sulfuryl fluoride, ethylene oxide, propylene oxide, ethyl bromide and ethyl formate—in a range of food matrices were developed. The food matrices included grain, oilseed, dried fruit, and nut. Methods: The new method was used to determine residue levels from a fumigant complex in food matrices by monitoring the change of the absorption of spiked standards and desorption of fumigant from fumigated samples. Results: Based on the observation, the process of physical sorption and chemisorption was defined. The equilibrium time of the sample analysis was chosen at 5 hours. The LODs of the fumigants were in the range of 0.03 to 1.99 ng/g. Response to a range of diluted authentic standards gave significant linear regressions (r2 &gt; 0.9983), and the RSDs were ≤8.7% at the 3 ng/g level of aged spiking standard, except for sulfuryl fluoride, for which the LOD was 1.99 ng/g and the RSD value was 39.7% (6.64 ng/g). Conclusions: The performance of the HS-SPME-GCMS method was more sensitive than the use of a gas syringe, except for sulfuryl fluoride. Highlights: An innovative multifumigant residue detection method based on HS-SPME sampling technology with gas chromatograph-mass selective detection (GC-MSD) analysis was established, including phosphine, methyl bromide, cyanogen, sulfuryl fluoride, ethylene oxide, propylene oxide, ethyl bromide, and ethyl formate; The first report of a sorption study of the process of physical sorption and chemisorption of residual fumigant in fruit and food matrices by an HS-SPME-GCMS method; Consider the effect of time on fumigant behavior in dried fruit, grain, and nut; The LODs of the fumigants were in the range of 0.03 to 1.99 ng/g.

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