Analysis of sulfonated naphthalene-formaldehyde condensates by ion-pair chromatography and their quantitative determination from aqueous environmental samples.
An ion-pair solid-phase extraction (IPE), ion-pair chromatography (IPC) procedure with fluorescence detection for the quantitative analysis of sulfonated naphthalene-formaldehyde condensates (SNFC) was developed, which provides full resolution of SNFC up to a degree of condensation n = 5 and partial resolution up to n = 15. Liquid chromatography-electrospray ionization-mass spectrometry confirmed that SNFC elute in the order of condensation. Response factors in fluorescence detection proved to be mass-constant, thereby allowing us to determine total SNFC amounts. With this IPC method, the weight- and the number-average molecular weights of these high-volume production chemicals (kiloton per annum), used as synthetic tanning agents, concrete plasticizers, and dispersants, can be determined. Recoveries in IPE range from 73 to 85% in river Rhine water and from 79 to 93% in tap water for n = 2 to n = 7 with limits of detection of 3-8 ng/L for individual homologues from 500 mL of water. The IPE-IPC procedure was applied to samples of secondary industrial effluents, river Rhine water, a river bank filtrate, and a groundwater sample. SNFC up to n = 6 were detected in the treated effluents. Total concentrations ranged from 208 micrograms/L in a secondary treated SNFC production effluent to < 1.4 micrograms/L in groundwater. These first analyses suggest a widespread occurrence of the lower oligomers of SNFC in the aquatic environment.
Wolf
C
C
DVGW-Technologiezentrum Wasser (TZW), Karisruhe, Germany. carmen.wolf@planet-interkom.de
Storm
T
T
Lange
F T
FT
Reemtsma
T
T
Brauch
H J
HJ
Eberle
S H
SH
Jekel
M
M
D002853:Chromatography, Liquid; D005557:Formaldehyde / Q000032:analysis*; D009281:Naphthalenes / Q000032:analysis*; D011108:Polymers / Q000032:analysis; D012722:Sewage / Q000032:analysis; D021241:Spectrometry, Mass, Electrospray Ionization; D014874:Water Pollutants, Chemical / Q000032:analysis*
D009281:Naphthalenes; D011108:Polymers; D012722:Sewage; D014874:Water Pollutants, Chemical; D005557:Formaldehyde