Glyphosate is a commonly used water-soluble herbicide. In recent years, with the increase of transgenic glyphosate-resistant crops, the amount of glyphosate has increased year by year, and it has become the most widely used and largest yield pesticide variety in the world. Very little of the herbicide glyphosate, which is used extensively in agriculture, is useful; most of it remains in the soil or floats in the atmosphere, and is washed into surface or groundwater by rainfall and runoff, causing water pollution. With the increasing demand and use of glyphosate in the world, the use of glyphosate pesticide will endanger human health. Therefore, the detection of glyphosate in water is an important analytical content in pesticide detection.
1.Test condition
instrument | HPLC S6000 |
Chromatographic column | Alphasil VC-C18, 4.6 × 250 mm, 5 μm |
Mobile phase | Acetonitrile-0.2% phosphate solution |
Detection wavelength (FL detector) | Excitation wavelength: 254 nm Emission wavelength: 302 nm |
Flow rate | 1.0mL/min |
Gradient elution
Time (min) | Acetonitrile (%) | 0.2% phosphate solution(%) |
0 | 35 | 65 |
10 | 25 | 75 |
15 | 80 | 20 |
20 | 35 | 65 |
25 | 35 | 65 |
2.Test result
Determination of standards
Glyphosate standards were tested using this protocol, and the results as shown in the figure below showed that the baseline separation between glyphosate and impurities was achieved.
Determination of actual samples
The actual samples were tested with this scheme, and the results were as shown in the figure below. The measured glyphosate content in tap water was 0.000382 μg/mL, and that in surface water was 0.002981 μg/mL.
Determination of detection limits
With s/n=3 as the detection limit and s/n=10 as the limit of quantitation, the national standard requires that the detection limit of glyphosate is 0.002μg /mL and the limit of quantitation is 0.008μg /mL. The detection limit of this experiment is 0.00025μg /mL and the limit of quantitation is 0.00005μg /mL, which is much higher than the national standard.
