Time-resolved fluoroimmunoassay as an advantageous approach for highly efficient determination of sulfonamides in environmental waters.
Using monoclonal antibodies labeled with Eu(3+) chelates, time-resolved fluoroimmunoassay (TRFIA) methods were developed for the determination of trace sulfamethazine (SMZ), sulfa-methoxazole (SMX), and sulfadiazine (SDZ) in environmental waters. Under the optimized conditions, the developed methods offered (i) low detection limits (9.8 ng/L SMZ, 6.1 ng/L SMX, and 5.4 ng/L SDZ, based on 90% inhibition) which were about 1 order of magnitude lower than that of the enzyme-linked immunosorbent assay (ELISA), (ii) high selectivity with no cross-reactivity (<0.05%) to similarly structured sulfonamides; (iii) high tolerance to variation of the sample pH (6.0-9.0) and salinity (0-100 mM), as well as the presence of humic acid (0-100 mg/L DOC) and heavy metals (0-1 mg/L concentration each of Cu(2+), Cd(2+), Hg(2+), Pb(2+), and As(V)) in the samples, and (iv) direct determination with low cost, high sample throughput, and low sample consumption (50-100 microL). The proposed TRFIA procedures were applied to determine sulfonamides in a variety of surface water and wastewater samples without sample pretreatment other than filtration. The satisfactory recoveries (64-127%) and reproducibilities (CV = 0.2-16%) achieved, as well as the good agreement with those given by liquid chromatography-tandem mass spectroscopy and ELISA methods, demonstrated the applicability of the proposed TRFIA methods for routine screening/quantification of sulfonamides in environmental waters.
Zhang
Zhen
Z
Chinese Academy of Sciences, Beijing 100085, China.
Liu
Jing-Fu
JF
Shao
Bing
B
Jiang
Gui-Bin
GB
D000911:Antibodies, Monoclonal; D004784:Environmental Monitoring / Q000379:methods*; D005063:Europium; D015200:Fluoroimmunoassay / Q000379:methods*; D013449:Sulfonamides / Q000737:chemistry*; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D000911:Antibodies, Monoclonal; D013449:Sulfonamides; D014874:Water Pollutants, Chemical; D014867:Water; D005063:Europium