DGT分析水中四环素类抗生素自由溶解态浓度

为分析四环素类抗生素的生物有效性，本研究自制了o-DGT装置，测定了结合相的回收率以及不同温度下污染物在扩散相的扩散系数，最终将该装置应用于天然水体中四环素类抗生素自由溶解态浓度的分析.结果表明，所制备的结合相对四环素类抗生素具有较强且稳定的结合能力，其单独存在时对溶液中四环素、土霉素、金霉素的回收率分别为（104.37±4.93）%，（80.29±4.41）%和（81.52±3.93）%；25℃时，3种四环素类抗生素在所制备的扩散相中扩散系数分别是（1.08±0.05）×10^-6，（1.07±0.18）×10^-6，（1.03±0.07）×10^-6cm²/s.抗生素浓度在0.2~10mg/L时，四环素、土霉素、金霉素的C_DGT占总量分别11.69%~30.21%、10.02%~29.25%和7.44%~34.10%.所制备的o-DGT装置性能稳定，可以为测定四环素类抗生素污染物生物有效性和自由溶解态浓度提供有效的参数.

Determination of the freely dissolved concentration of tetracyclines in water with diffusive gradients in thin-films technology(DGT)

In order to determine the bioavailability of tetracyclines (TCs), a diffusive gradients in thin-films for organic technology (o-DGT) device was developed. The diffusivity of the diffused phase and the recovery rate of the combined phase were measured at different temperatures. The results showed that the combined phase had strong and stable capacity on the exaction of TCs when solely presented with recovery rates of (104.37±4.93)%, (80.29±4.41)%, and (81.52±3.93)% for tetracycline (TC), oxytetracycline (OTC) and chlorotetracycline (CTC), respectively. The diffusion coefficients of TC, OTC, CTC were (1.08±0.05)×10^-6, (1.07±0.18)×10^-6, (1.03±0.07)×10^-6 cm²/s, respectively. With the total concentrations of TCs among 0.2~10.0mg/L, the ratios of C_DGT to total concentration in natural water were 11.69%~30.21%, 10.02%~29.25% and 7.44%~34.10% for TC, OTC, CTC, respectively. Thus, the o-DGT device showed a stable performance and could provide effective measurement parameters for the bioavailability determination of tetracyclines.