Fenitrothion Solution: Properties, Uses & Safety Guide

Fenitrothion solution is a precisely formulated organophosphate reference standard used in analytical, environmental, and toxicological research to quantify pesticide residues and study cholinesterase inhibition mechanisms.

Chemical Name

O,O-Dimethyl O-(3-methyl-4-nitrophenyl) phosphorothioate

CAS Number

122-14-5

Molecular Formula

C₉H₁₂NO₅PS

Molecular Weight

277.23 g/mol

Mechanism of Action

Irreversible inhibitor of acetylcholinesterase (AChE) via phosphorylation of the active-site serine residue

Primary Research Use

Pesticide residue reference standard for GC, GC-MS, and HPLC analysis

Storage Condition

Store at 2–8 °C, away from light and ignition sources

SKU

F114189

Chemical Identity and Physical Properties

Fenitrothion (CAS 122-14-5) is an organophosphate insecticide belonging to the phosphorothioate subclass. Its systematic IUPAC name is O,O-dimethyl O-(3-methyl-4-nitrophenyl) phosphorothioate, with the molecular formula C₉H₁₂NO₅PS and a molecular weight of approximately 277.23 g/mol.

In its pure form, fenitrothion is a yellow-to-brownish oily liquid with a characteristic garlic-like odor. Key physical parameters include a boiling point of approximately 140–145 °C at 0.1 mmHg, low water solubility (~19 mg/L at 20 °C), and high solubility in common organic solvents such as acetone, ethanol, dichloromethane, and toluene. Its log P (octanol/water partition coefficient) is approximately 3.3, indicating significant lipophilicity relevant to environmental fate and bioaccumulation studies.

Aladdin Scientific supplies fenitrothion as a ready-to-use solution (SKU: F114189), typically dissolved in an appropriate organic solvent (e.g., acetonitrile or methanol) at a certified concentration, enabling direct use as an analytical calibration or spiking standard without further gravimetric preparation.

Research and Analytical Applications

Fenitrothion solution finds use across multiple scientific disciplines, primarily as a certified reference material or spiking solution in the following contexts:

• Pesticide Residue Analysis: Fenitrothion is a regulated pesticide with maximum residue limits (MRLs) set by regulatory bodies including the EU, Codex Alimentarius, and national authorities. The solution serves as a calibration standard in gas chromatography (GC), GC coupled to mass spectrometry (GC-MS/MS), and high-performance liquid chromatography (HPLC) methods used to quantify residues in food matrices (cereals, fruits, vegetables), water, and soil.
• Environmental Monitoring: Due to its persistence in aquatic and terrestrial environments, fenitrothion is routinely monitored in surface water, groundwater, and sediment samples. The solution enables preparation of matrix-matched calibration curves and method validation spike sets.
• Toxicological and Mechanistic Studies: As an acetylcholinesterase (AChE) inhibitor, fenitrothion solution is used in in vitro enzyme inhibition assays to characterize inhibition kinetics (IC₅₀ determination), and in cell-based models to investigate organophosphate neurotoxicity pathways.
• Ecotoxicology: Researchers use certified fenitrothion solutions to prepare dosing solutions for aquatic toxicity tests (e.g., Daphnia LC₅₀, fish acute toxicity assays) and terrestrial organism exposures in accordance with OECD test guidelines.
• Method Development and Validation: The solution is an essential tool for validating multi-residue methods, confirming instrument linearity, and generating proficiency-testing spiked samples in accredited laboratories.

Safe Handling, Storage, and Disposal

Fenitrothion is a toxic organophosphate compound, and all work with its solution must follow appropriate occupational health and safety protocols.

Personal Protective Equipment (PPE): Wear chemical-resistant nitrile or neoprene gloves, a laboratory coat, and safety goggles when handling fenitrothion solution. Where aerosol or vapor generation is possible, work inside a certified chemical fume hood. A properly fitted half-face respirator with organic vapor cartridges should be available for use if ventilation is inadequate.

Storage: Store the solution at 2–8 °C in a tightly sealed container, protected from light. Keep away from heat, open flames, oxidizing agents, and strong bases. Stability should be confirmed according to the supplier's certificate of analysis (CoA); typical shelf life for solution standards is 12–24 months when stored properly. Segregate from foodstuffs and incompatible chemicals.

First Aid Measures: In case of skin contact, remove contaminated clothing and wash affected area with soap and water for at least 15 minutes. For eye contact, irrigate immediately with copious water for 15 minutes and seek medical attention. If ingested or inhaled, remove to fresh air and seek immediate medical assistance; atropine and pralidoxime (PAM) are antidotes used by trained medical personnel for organophosphate poisoning.

Waste Disposal: Dispose of fenitrothion solution and contaminated materials as hazardous chemical waste in accordance with local, national, and international regulations. Do not pour down the drain or into the environment. Consult your institution's environmental health and safety (EHS) office for approved disposal procedures.

Regulatory Status and Quality Considerations

Fenitrothion is registered as a pesticide active substance in numerous jurisdictions, though regulatory status varies. It has been reviewed under the EU pesticide regulation framework and is subject to monitoring programs by agencies such as the European Food Safety Authority (EFSA) and the US Environmental Protection Agency (EPA). Researchers should verify the current registration and use-authorization status in their country before initiating studies involving field-use scenarios.

For analytical reference applications, the purity and certified concentration of the solution are critical quality parameters. When selecting a fenitrothion solution for validated analytical methods, laboratories should request:

• Certificate of Analysis (CoA) specifying purity (typically ≥98% for reference-grade material), confirmed concentration, solvent identity, and expiry date.
• Traceability documentation linking the material to a recognized primary standard or national metrology institute (NMI) where applicable.
• Safety Data Sheet (SDS/MSDS) conforming to GHS/REACH requirements for hazard communication and safe use.

Aladdin Scientific's Fenitrothion solution (F114189) is intended for research and analytical laboratory use. Users in regulated testing environments (e.g., ISO 17025-accredited laboratories) should confirm that the material meets method-specific acceptance criteria for calibrant or spiking-solution use.

Frequently asked questions

What solvent is used in Aladdin's Fenitrothion solution (F114189)?

The specific solvent and certified concentration are detailed on the product's Certificate of Analysis (CoA). Common solvents for organophosphate reference solutions include acetonitrile, methanol, or isooctane. Please request the CoA from Aladdin Scientific at the time of order to confirm solvent identity before use.

How should Fenitrothion solution be stored to maintain stability?

Fenitrothion solution should be stored at 2–8 °C in a tightly closed amber or foil-wrapped glass vial, away from light, heat, and incompatible substances such as strong oxidizers and bases. Under these conditions, solution reference standards typically remain stable for 12–24 months; always check the expiry date on the CoA and discard expired material as hazardous waste.

Is Fenitrothion solution suitable for use as a calibration standard in GC-MS pesticide residue methods?

Yes. Fenitrothion solution at a known and certified concentration is widely used as a calibration standard in GC and GC-MS/MS multi-residue pesticide methods for food, water, and environmental matrices. Users should verify that the material's purity and traceability documentation meet the acceptance criteria of their validated method and any relevant accreditation body requirements.

What are the main health hazards of Fenitrothion and how can exposure be minimized?

Fenitrothion is an organophosphate cholinesterase inhibitor. Acute exposure via skin absorption, inhalation, or ingestion can cause cholinergic toxicity symptoms including miosis, excessive secretions, muscle weakness, and in severe cases, respiratory failure. Exposure is minimized by working in a fume hood, wearing nitrile gloves, lab coat, and eye protection, and following all SDS guidance. Medical surveillance and baseline cholinesterase activity testing are advisable for personnel with frequent exposure.

References

1. World Health Organization (WHO). Fenitrothion in Drinking-water: Background document for development of WHO Guidelines for Drinking-water Quality. WHO/SDE/WSH/03.04/60. Geneva: WHO, 2004.
2. European Food Safety Authority (EFSA). Conclusion on the peer review of the pesticide risk assessment of the active substance fenitrothion. EFSA Journal. 2006;4(2):68r.
3. Tomlin CDS, ed. The Pesticide Manual: A World Compendium. 16th ed. Alton, Hampshire: British Crop Production Council; 2012.
4. Eto M. Organophosphorus Pesticides: Organic and Biological Chemistry. Cleveland: CRC Press; 1974.

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.