Evaluation of Microwave Irradiation for Analysis of Carbonyl Sulfide, Carbon Disulfide, Cyanogen, Ethyl Formate, Methyl Bromide, Sulfuryl Fluoride, Propylene Oxide, and Phosphine in Hay

2007 ◽  
Vol 55 (1) ◽  
pp. 32-37 ◽  
Author(s):  
Yonglin Ren ◽  
Daphne Mahon
Keyword(s):  
Microwave Irradiation ◽  
Carbon Disulfide ◽  
Propylene Oxide ◽  
Methyl Bromide ◽  
Carbonyl Sulfide ◽  
Ethyl Formate ◽  
Sulfuryl Fluoride

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 > 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.

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

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 > 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.

scholarly journals Analysis of Fumigant Residues—A Critical Review

1999 ◽  
Vol 82 (6) ◽  
pp. 1261-1280 ◽  
Author(s):  
James M Desmarchelier ◽  
Yong-Lin Ren
Keyword(s):  
Analytical Chemistry ◽  
Methyl Bromide ◽  
Critical Review ◽  
Carbonyl Sulfide ◽  
Ethyl Formate

Abstract This review concentrates on the main fumigants currently applied to commodities: phosphine (PH3) and methyl bromide (CH3Br). It discusses possible new fumigants, such as carbonyl sulfide (COS) and ethyl formate (EtF), that may be able to be applied in such a way that “residues” after fumigation do not exceed the range of natural levels. The review aims to raise some general issues and to suggest some general conclusions from a synthesis of studies on analytical chemistry and on fumigant behavior.

scholarly journals The influence of dissolved organic matter on the marine production of carbonyl sulfide (OCS) and carbon disulfide (CS<sub>2</sub>) in the Peruvian upwelling

Ocean Science ◽  
2019 ◽  
Vol 15 (4) ◽  
pp. 1071-1090 ◽  
Author(s):  
Sinikka T. Lennartz ◽  
Marc von Hobe ◽  
Dennis Booge ◽  
Henry C. Bittig ◽  
Tim Fischer ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Carbon Disulfide ◽  
Solid Phase ◽  
Carbonyl Sulfide ◽  
Limiting Factors ◽  
Biogeochemical Model ◽  
Fluorescent Dissolved Organic Matter ◽  
Process Understanding ◽  
Future Emission

Abstract. Oceanic emissions of the climate-relevant trace gases carbonyl sulfide (OCS) and carbon disulfide (CS2) are a major source to their atmospheric budget. Their current and future emission estimates are still uncertain due to incomplete process understanding and therefore inexact quantification across different biogeochemical regimes. Here we present the first concurrent measurements of both gases together with related fractions of the dissolved organic matter (DOM) pool, i.e., solid-phase extractable dissolved organic sulfur (DOSSPE, n=24, 0.16±0.04 µmol L−1), chromophoric (CDOM, n=76, 0.152±0.03), and fluorescent dissolved organic matter (FDOM, n=35), from the Peruvian upwelling region (Guayaquil, Ecuador to Antofagasta, Chile, October 2015). OCS was measured continuously with an equilibrator connected to an off-axis integrated cavity output spectrometer at the surface (29.8±19.8 pmol L−1) and at four profiles ranging down to 136 m. CS2 was measured at the surface (n=143, 17.8±9.0 pmol L−1) and below, ranging down to 1000 m (24 profiles). These observations were used to estimate in situ production rates and identify their drivers. We find different limiting factors of marine photoproduction: while OCS production is limited by the humic-like DOM fraction that can act as a photosensitizer, high CS2 production coincides with high DOSSPE concentration. Quantifying OCS photoproduction using a specific humic-like FDOM component as proxy, together with an updated parameterization for dark production, improves agreement with observations in a 1-D biogeochemical model. Our results will help to better predict oceanic concentrations and emissions of both gases on regional and, potentially, global scales.

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.

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