| CAS Number | 94-75-7 |
|---|---|
| Molecular Formula | C8H6Cl2O3 |
| Molecular Weight | 221.030 |
| InChI Key | OVSKIKFHRZPJSS-UHFFFAOYSA-N |
| LogP | 2.81 |
| Synonyms |
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Applications:
Uv-Vis Spectrum of 2,4-Dichlorophenoxyacetic Acid
February 13, 2026

If you are looking for optimized HPLC method to analyze 2,4-Dichlorophenoxyacetic acid check our HPLC Applications library
For optimal results in HPLC analysis, it is recommended to measure absorbance at a wavelength that matches the absorption maximum of the compound(s) being analyzed. The UV spectrum shown can assist in selecting an appropriate wavelength for your analysis. Please note that certain mobile phases and buffers may block wavelengths below 230 nm, rendering absorbance measurement at these wavelengths ineffective. If detection below 230 nm is required, it is recommended to use acetonitrile and water as low UV-transparent mobile phases, with phosphoric acid and its salts, sulfuric acid, and TFA as buffers.
For some compounds, the UV-Vis Spectrum is affected by the pH of the mobile phase. The spectra presented here are measured with an acidic mobile phase that has a pH of 3 or lower.
2,4-D Retention on Primesep 100 and Obelisc R
September 14, 2015

2,4-D makes up half of the formula for Agent Orange, the defoliant that was used during the Vietnam War and Malayan Emergency. Commonly used in lawn and turf pesticides, 2,4-D is typically mixed with other pesticides such as mecoprop and dicamba. It was analyzed on Primesep 100 and Obelisc R. Primesep 100 separates using reverse-phase and acidic ion-pairing groups. Obelisc R has many modes of separation which allow it to tune retention. Method is LC/MS compatible and conditions could be replicated to retain many pesticides.
| Column | Obelisc R, 2.1×150 mm, 5 µm, 100A |
| Mobile Phase | Gradient MeCN – 25-70% |
| Buffer | Gradient AmAc pH 3.0- 30-60 mM |
| Flow Rate | 0.4 ml/min |
| Detection | UV, 270 nm |
| Column | Obelisc R, 2.1×150 mm, 5 µm, 100A |
| Mobile Phase | Gradient MeCN – 10-70% |
| Buffer | Gradient AmAc pH 3.0- 20-60 mM |
| Flow Rate | 0.4 ml/min |
| Detection | UV, 270 nm |
| Column | Primesep 100, 2.1×150 mm, 5 µm, 100A |
| Mobile Phase | Gradient MeCN – 10-70% |
| Buffer | Gradient AmAc pH 3.0- 20-60 mM |
| Flow Rate | 0.4 ml/min |
| Detection | UV, 270 nm |
| Class of Compounds |
Insecticide, Pesticide, Hydrophobic, Ionizable |
| Analyzing Compounds | 2,4-D |
Application Column
Obelisc R
SIELC has developed the Obelisc™ columns, which are mixed-mode and utilize Liquid Separation Cell technology (LiSC™). These cost-effective columns are the first of their kind to be commercially available and can replace multiple HPLC columns, including reversed-phase (RP), AQ-type reversed-phase, polar-embedded group RP columns, normal-phase, cation-exchange, anion-exchange, ion-exclusion, and HILIC (Hydrophilic Interaction Liquid Chromatography) columns. By controlling just three orthogonal method parameters - buffer concentration, buffer pH, and organic modifier concentration - users can adjust the column properties with pinpoint precision to separate complex mixtures.
Select optionsPrimesep 100
The Primesep family of mixed-mode columns offers a wide variety of stationary phases, boasting unprecedented selectivity in the separation of a broad array of chemical compounds across multiple applications. Corresponding Primesep guard columns, available with all stationary phases, do not require holders. SIELC provides a method development service available to all customers. Inquire about our specially-tailored custom LC-phases for specific separations.
Select options

