UV absorber UV-T

Catalog NumberHG27503817

CAS Number27503-81-7

CategoryUV Absorbers

Molecular Weight

274.3

Molecular Formula

C13H10N2O3S

Appearance

White or off-white powder

Storage

Keep container tightly closed and dry and storage in cool place

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Case Study

UV-Activated Percarbonate Degradation of the Sunscreen Filter PBSA via Carbonate and Superoxide Radicals

Lai, Webber Wei-Po, et al. Environmental Technology & Innovation 39 (2025): 104257.

Phenylbenzimidazole sulfonic acid (PBSA), a water-soluble organic UV-B filter that persists in aquatic environments, was degraded using a UV-activated sodium percarbonate (UV/SPC) process as an alternative to UV/H₂O₂.
Experimental Protocol: Experiments used capped quartz reactors, an 8 W low-pressure 254 nm mercury lamp, 5 mM phosphate buffer, an initial PBSA concentration of 10 mg/L and 100 mg/L SPC; scavenger tests employed tert-butanol (TBA), phenol (PhOH), para-benzoquinone (pBQ) and furfuryl alcohol (FFA) at 31.85 mM (pBQ 12.74 mM), and reactive species were identified by EPR with DMPO and TEMP spin traps. PBSA was quantified by HPLC, byproducts by UHPLC-QTOF-MS, and mineralization by TOC.
Performance Evaluation: PBSA was completely removed within 15 min (k_obs = 0.336 min^-1), far exceeding UV/H₂O₂ (k_obs = 0.017 min^-1), and the electrical energy per order was 45.7 kW·hr order^-1 m^-3, about 95% lower than UV/H₂O₂ (903.5). TBA reduced k_obs to 0.096 min^-1, while PhOH and pBQ gave 0.002 min^-1 and FFA 0.067 min^-1, confirming ·OH, CO₃^·-, O₂^·- and ¹O₂ involvement. ·OH contributed only 4.26%, 6.80% and 12.16% at pH 4, 7 and 10. Thirteen byproducts formed via hydroxylation, oxidation, imidazoline ring cleavage, desulfonation and benzene ring cleavage; TOC removal was only 12% after 120 min, yet no obvious toxicity appeared. Real water systems were fully treated within 50 min.

UV254nm/H2O2 Degradation of PBSA: Fourteen Byproducts and Mineralization Kinetics

Abdelraheem, Wael HM, et al. Chemical Engineering Journal 288 (2016): 824-833.

2-Phenylbenzimidazole-5-sulfonic acid (PBSA), a widely used active sunscreen UV filter, was investigated for its degradation byproducts, pathways and kinetics under the UV_254nm/H₂O₂ advanced oxidation process.
Experimental Protocol: Photochemical experiments used two bench-scale reactors each housing two low-pressure 15 W Hg lamps emitting primarily at 254 nm, with an average UV fluence rate of about 0.1 mW cm^-2 across 10 mL solutions. Two conditions were studied: 1 µM pollutant with 1 mM H₂O₂, and 50 µM pollutant with 5 mM H₂O₂. Phosphate buffer (5.0 mM, pH 6.89) was used for second-order rate-constant determinations with pCBA as reference. PBSA and related compounds (2-PIZ, BZ, BD, BZD) were quantified by HPLC-PDA, byproducts were identified by LC/Q-TOF-ESI-MS, and mineralization was followed via sulfate, ammonium, nitrate and TOC measurements.
Performance Evaluation: No obvious photolysis occurred under UV alone, but with 1 mM H₂O₂, 12 min of irradiation removed about 80% of 2-PIZ, 70% of PBSA and BZ, 65% of BD and 60% of BZD, with complete removal at 48 min. Rate constants followed k_obs: 2-PIZ (2.14 × 10^-2) > PBSA (1.73 × 10^-2) > BZ (1.47 × 10^-2) > BD (1.44 × 10^-2) > BZD (1.10 × 10^-2) min^-1. Fourteen byproducts were identified, including hazardous benzamide (BD) and benzamidine (BZD). Sulfate release was fast over 0-48 min (0.288 µM min^-1) then slow (0.149 µM min^-1), reaching about 70% S mineralization; TOC removal at 190 min was 23% for PBSA.

• Molecular Weight: 274.3
• Molecular Formula: C13H10N2O3S
• Appearance: White or off-white powder
• Storage: Keep container tightly closed and dry and storage in cool place