Simple spectrophotometric determination of nonionic surfactants with a cationic azo dye

Maiko Nakata, Yoshiyuki Murata, Mikiro Tada, Yasuaki Shimoishi

Research output: Contribution to journalArticlepeer-review


A simple spectrophotometric method for the determination of polyoxyethylene nonionic surfactants, such as TritonX-100 with 1-(p-phenylphenacyl)-4-(4- aminonaphthylazo)-pyridinium bromide (PPAP), was developed. PPAP was synthesized by quarternizing 4-(4-aminonaphthylazo)-pyridine with p-phenylphenacyl bromide. Because PPAP was easily associated with nonionic surfactants to produce a blue ion associate in aqueous solution, the concentration of nonionic surfactants were determined by measuring the absorbance of ion associates at 612 nm. The apparent molar absorptivity of the TritonX-100 ion associate was 1.0 × 103 dm3 mol-1 cm-1 at 612 nm. The calibration graph for TritonX-100 was linear over the range from 6.0 × 10-5 to 8.0 × 10-4 M, and the relative standard deviation for 5.6 × 10-4 M of TritonX-100 was 2.0%. The proposed method was applied to the determination of nonionic surfactants in commercial domestic detergents.

Original languageEnglish
Pages (from-to)899-902
Number of pages4
Issue number10
Publication statusPublished - Oct 2003


  • 1-(p-phenylphenacyl)-4-(4- aminonaphthylazo)-pyridinium bromide
  • Briji 35
  • Nonionic surfactant
  • Spectrophotometry
  • TritonX-100

ASJC Scopus subject areas

  • Analytical Chemistry


Dive into the research topics of 'Simple spectrophotometric determination of nonionic surfactants with a cationic azo dye'. Together they form a unique fingerprint.

Cite this