Product Identity and Physical Properties
Phenylmethanesulfonyl fluoride (CAS 329-98-6), also known by IUPAC name Phenylmethanesulfonyl fluoride and synonyms α-Toluenesulfonyl fluoride, Benzylsulfonyl fluoride, PMSF, and Phenylmethylsulfonyl fluoride, is a standard reagent for protease inhibition in protein biochemistry. This compound appears as a white to off-white crystalline powder with a distinct aromatic odor.
The compound exhibits moderate lipophilicity (XLogP 1.9), which facilitates solubility in organic solvents while limiting aqueous stability. Its sulfonyl fluoride functional group is critical for irreversible binding to active-site serine residues in proteolytic enzymes, making it a standard tool in cell lysis buffers and protein extraction workflows.
Grade Specifications and Quality Parameters
This product is supplied as ≥98.5% purity determined by gas chromatography (GC). The grade designation indicates suitability for general biochemical and analytical applications where high purity is required but pharmacopeial certification is not mandatory. Below is a comparison of available grades for Phenylmethanesulfonyl fluoride.
| Parameter | Grade (≥98.5% GC) | BioReagent Grade | ACS Reagent Grade |
|---|---|---|---|
| Assay (GC) | ≥98.5% | ≥99.0% | ≥99.0% |
| Physical Form | Powder | Powder or crystalline | Crystalline |
| Water Content | Not specified | ≤0.5% | ≤0.2% |
| Heavy Metals | Not specified | ≤0.005% | ≤0.001% |
| Documentation | CoA, SDS | CoA, SDS, Certificate of Origin | CoA, SDS, ACS lot analysis |
The ≥98.5% (GC) specification ensures minimal interference from residual toluene, benzyl chloride, or other synthetic byproducts. Quality Level parameters are maintained through routine batch testing, with each lot undergoing GC purity verification and physical appearance checks before release.
Handling, Storage, and Safety
PMSF carries a GHS Signal Word of Danger due to its acute toxicity and corrosive properties. Hazard codes include H302 (Harmful if swallowed), H315 (Causes skin irritation), H318 (Causes serious eye damage), and H334 (May cause allergy or asthma symptoms or breathing difficulties if inhaled).
Storage requirements mandate a cool, dry environment away from moisture and strong oxidizing agents. The Storage Class is 6.1 (Toxic substances), and the Water Hazard Class (WGK) is 3 (high hazard to waters). The flash point is 113 °C (235 °F), requiring standard flammable liquid precautions during handling.
Recommended personal protective equipment includes chemical-resistant gloves (nitrile or neoprene), safety goggles with side shields, and a lab coat. For operations generating dust or aerosols, use a NIOSH-approved particulate respirator. Work should be conducted in a fume hood to minimize inhalation risk.
Solubility and Solution Preparation
PMSF exhibits excellent solubility in anhydrous organic solvents, with stock solutions prepared at 200 mM in ethanol, methanol, or 2-propanol. These stock solutions remain stable for months when stored at 4 °C in sealed, moisture-free containers. The compound is unstable in aqueous media, with a half-life of approximately 30–60 minutes at pH 7.0 and 25 °C due to hydrolysis.
For analytical applications, prepare fresh working solutions by diluting stock into the aqueous buffer immediately before use. Typical working concentrations range from 0.1 to 1.0 mM in lysis buffers. Do not store diluted aqueous solutions; discard any unused portion after 2 hours. For HPLC analysis, dissolve in 100% methanol or acetonitrile at 1–10 mg/mL concentration, filtering through a 0.45 µm PTFE membrane before injection.
Applications in Analytical and Research Settings
PMSF is primarily employed in lysis buffers to preserve proteins of interest during cell or tissue homogenization. By irreversibly inhibiting serine proteases (e.g., trypsin, chymotrypsin, thrombin), it prevents proteolytic degradation that would otherwise compromise downstream analysis. The compound is particularly valuable in western blotting, immunoprecipitation, and enzyme activity assays.
In analytical chemistry, PMSF serves as a reference standard for GC method development and validation. Its distinct retention time and response factor make it suitable for quantifying residual PMSF in pharmaceutical intermediates. NMR spectroscopy (¹H and ¹⁹F) can confirm structural integrity, with characteristic signals at δ 4.5 ppm (CH₂) and δ 7.3 ppm (aromatic) in CDCl₃.
The powder form (≥98.5% GC) is compatible with HPLC-UV detection at 210–220 nm and GC-FID analysis. For pharmaceutical reference standard applications, each batch is tested for identity, purity, and residual solvents per ICH Q3C guidelines.
Supplier Selection Guide
Research quantities of Phenylmethanesulfonyl fluoride (CAS 329-98-6) are available from major suppliers. For bulk production, formal quotations with CoA, SDS, and lead time are available within 24 hours — contact our team to inquire about current pricing and discuss your requirements.
A: PMSF is a serine protease inhibitor used in lysis buffers to prevent protein degradation during cell or tissue homogenization. It is essential for preserving protein integrity in western blotting, immunoprecipitation, and enzyme activity assays.
A: It indicates the minimum purity determined by gas chromatography. Each lot is tested to ensure the assay meets or exceeds 98.5% by area normalization, with residual solvents and impurities below established thresholds.
A: Store in a tightly sealed container at 2–8 °C, protected from moisture and light. Stock solutions in anhydrous ethanol or 2-propanol are stable for months at 4 °C. Aqueous solutions must be prepared fresh and used within 2 hours.
A: Gas chromatography (GC) with FID detection is the primary method. HPLC-UV at 210 nm, ¹H and ¹⁹F NMR spectroscopy, and melting point determination (50–54 °C) are also commonly employed for identity and purity confirmation.
A: Each shipment includes a Certificate of Analysis (CoA) with GC purity data, a Safety Data Sheet (SDS) per GHS/OSHA requirements, and a lot-specific label. Bulk orders may include additional documentation such as GMP certificates and residual solvent reports upon request.
Phenylmethanesulfonyl fluoride (PMSF)
CAS: 329-98-6
Grade: ≥98.5% (GC)
Form: Powder
Packaging: 1 g, 5 g, 25 g
Applications: Protease inhibition, protein isolation, analytical reference standard
