Occurrence,spatial and seasonal variation,and environmental risk of pharmaceutically active compounds in the Pearl River basin,South China

The occurrence,fate,and environmental risk of 40 pharmaceutically active compounds(PhACs)from surface waters and sediments were comprehensively investigated in the Beijiang River,Xijiang River,and Maozhou River of the Pearl River basin,South China.Salicylic acid and diclofenac(antiinflammatory drugs),gemfibrozil(a lipid regulator),carbamazepine(an antiepileptic drug),diazepam(a psychoactive drug),and 2-methyl-4-chloro-phenoxyacetic acid(MCPA,a pesticide)were the most ubiquitous compounds in the studied region.The average concentrations of detected PhACs in surface waters and sediments ranged from 0.17 to 19.1 ng/L and 0.10 to 10.4 ng/g,respectively.Meanwhile,PhACs concentration in surface waters and sediments varied greatly among and within the Beijiang River,Xijiang River,and Maozhou River.The largest annual flux of PhACs of the Xijiang River and Beijiang River was more than 11000 kg per annum,whereas only 25.7 kg/a in the Maozhou River.In addition,the estimated emissions of PhACs in the Beijiang River,Xijiang River,and Maozhou River ranged respectively from 0.28 to 4.22 kg/a,0.12 to 6.72 kg/a,and 6.66 to 91.0 kg/a,and the backestimated usage varied with a range from 12.0 to 293 kg/a,6.79 to 944 kg/a,368 to 17459 kg/a.Moreover,the emissions of PhACs showed a close relationship with the gross domestic product(GDP)of each city along the Pearl River.The environmental risk assessment suggested that diazepam and ibuprofen had a moderate risk in this region.

Facile interfacial synthesis of gold micronails with adjustable length and roughness and their superior SERS properties for the detection of p-aminothiophenol Author links open overlay panel

Au hierarchical architectures with special morphology and structures are strongly desired in varied applications.Herein,a simple synthesis method was developed for the one-step preparation of Au micronails(MNs)at the planar liquid-liquid interface under mild conditions.The well-defined Au MNs were grown and constructed at CHCl_(3)-H_(2)O interface at room temperature using aniline in CHCl_(3)as reducing agent and HAuCl_(4)in H_(2)O as precursor and no surfactant or seed is required.The intriguing Au MNs with rough surface consist of big heads and thin rods,just like iron nails in outline.Furthermore,through simple changing the reagent concentrations,the length and surface roughness of Au MNs can be adjusted conveniently.The effects of a series of factors on the morphology and structure of the products are studied in detail.With p-aminothiophenol as a molecular probe,the as-obtained Au MNs all exhibit dramatically improved surface enhanced Raman scattering sensitivity and high reproducibility,the enhancement factor and limit of detection of Au MNs are 5.4×10^(5)and 1.0×10^(-10),respectively.