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Determination of deltamethrin content from netting
Outline of method
Deltamethrin is extracted from net into extraction 1,4-dioxane, added hexachlorobenzene (IS). Take sample solution is filtered through 0.45 micron membrane filter was injected in a gas chromatography equipped with a uECD detector.
Apparatus
| Gas chromatography (Agilent 6890N) |
| - Column |
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HP-5 |
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30 m x 0.32 mm x 0.25 micron |
| - Carrier |
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Helium, at 40 cm/sec (2 ml/min) |
| - Oven |
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180-260 °C at 25 °C/min |
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260-300 °C at 5 °C/min |
| - Injection |
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split, 1uL |
| - Detector |
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uECD, 320 °C |
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Nitrogen, 60 mL/min makeup gas |
Reagents
1. Deltamethrin standard. Analytical standard of known purity
2. Hexachlorobenzene (IS). Analytical reagent grade
3. 1,4-dioxane. Analytical reagent grade
Preparation of calibration solutions
1. Deltamethrin –Stock standard solution
Weigh of deltamethrin 0.0250 g in volumetric flask (100 ml). Dissolve and adjust volume with 1,4-dioxane. Labelled DSS.
2. Internal Standard
Stock solution
To weigh of hexachlorobenzene 0.5 g in volumetric flask (50 ml). Dissolve and adjust with 1,4-dioxane. Labelled ISS.
Working solution
Dilute Internal Standard stock (ISS) with 1,4-dioxane ratio 1 : 20. Labelled ISW.
Calibration Curve standard deltamethrin solution
| Code |
ISW(ml) |
DSS(ml) |
ES(ml) |
Concentration of deltamethrin (mg/sq.m)
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| DSW-1 |
1 |
1 |
18 |
24.75 |
| DSW-2 |
1 |
2 |
17 |
49.50 |
| DSW-3 |
1 |
3 |
16 |
74.25 |
Extraction of deltamethrin from netting
Use sample cutter, cut a circle of exact 0.01 sq.m out of sample net. Weigh the sample net into 50 ml screw-capped vial .Add Internal standard (ISW) 1 ml , 1,4-dioxane 19 ml and magnetic bar. Replace the cap closely. Extract on hotplate stirrer 110 °C for 15 min. Cool the extract to room temperature. The sample solution can be used directly.
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