Determination of Benzidine and 3,3'-Dichlorobenzidine in Wastewater by Liquid Chromatography with UV and Electrochemical Detection

Abstract

The title compounds are on the EPA priority pollutant list. Therefore, a sensitive method for their measurement is required. The liquid chromatographic method employs a LiChrosorb RP-2 column, 45% acetonitrile (pH 5) mobile phase, UV detection at 280 nm, and electrochemical detection at +0.70 volts applied potential. The three-electrode electrochemical cell described contains a tubular carbon-black/polyethylene working electrode that permits detection of sub-part-per-billion levels in a 50 microliter injection permits detection of 2 ppb benzidine and dichlorobenzidine. Recoveries from fortified wastewater of benzidine at 1 to 6 ppb and dichlorobenzidine at 3 to 12 ppb levels were 83% and 87%, respectively.

Predicting the Multicomponent Removal of Surrogate Compounds by a Fixed‐Bed Adsorber

“…Plug flow PSDM and HSDM mass transfer models were used to determine the accuracy of predicting the breakthrough profiles of single-and multisolute studies. D,q = PDFC x SPDFR (5) Thus, the surrogate compound would more closely represent the way the compounds of its group pack into the pores of the GAC. This technique was used to verify the proper selection of the 14 surrogate compounds and to obtain a closer estimate of the adsorption isotherms for compounds within the specific group.…”

Electrochemical Detection in Hight-Performance Liquid Chromatography

“…catechol have been analyzed as impurities in phenol, 370 trace concentrations of phenolic compounds have been determined in water, 87 ' 99 ' 165 and phenolic residues 371 and 2-phenylphenol in orange rind 372 have also been analyzed. Further, trace amounts of aminophenols, 373 In comparison with U V detection, the LCEC system provides higher sensitivity 384 and, thus, better separation. Compared with gas chromatography with electron-capture detection for chlorinated compounds, where a similar sensitivity is attained, LCEC does not require time-consuming clean-up procedures.…”

“…Using LCEC, aromatic carcinogens, 381 aniline-derived carbamates (detection limit of 3 ng), 382 benzidine and its metabolites in urine, 19 ' 383 and its derivatives in waste waters 384 ' 385 have been determined. Chlorinated anilines have been analyzed in urine with both EC 483 and U V detection 386 ' 387 and a detection limit of 2 to 3 pmol has been found for EC.…”

Ultra-trace level determinations of benzidine and dichlorobenzidine residues in surface water by liquid chromatography-electrospray ionization tandem mass spectrometry

“…A wide range of analytical techniques has been developed to monitor these contaminants at trace levels in environmental samples. Most of these procedures are based on determining BZ and DCBZ in environmental water by voltammetry [6], gas chromatography with electron capture (GC-ECD) [7], electron-impact (EI) mass spectrometry (MS) [8,9], highperformance liquid chromatography (HPLC) [2,[10][11][12][13][14][15][16][17]. One group used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to identify photodegradation products of BZ and DCBZ, but they did not use that method to determine BZ and DCBZ in water [18].…”