[Source and distribution characteristic of atmospheric organochlorine pesticides in the Pearl River Estuary and adjacent South China Sea].

Ship-board air samples were collected during the winter and spring cruise to the Pearl River Estuary (PRE) and adjacent South China Sea (SCS) in 2003 and were analyzed for organochlorine pesticides (OCPs). Meanwhile, air samples were collected at land-based sites in Guangzhou and Zhongshan for comparison. Results indicated that the detected OCPs were mainly of HCHs, DDTs and chlordane, its concentration ranged between 13-99, 73-390, 63-224 pg/m3 and 10-106, 429-1003, 1724-9638 pg/m3 during the winter and spring cruise, respectively.

Characterizing ionic species in PM2.5 and PM10 in four Pearl River Delta cities, south China.

PM2.5 and PM10 samples were collected at four major cities in the Pearl River Delta (PRD), South China, during winter and summer in 2002. Six water-soluble ions, Na+, NH4+, K+, Cl-, NO3- and SO4(2-) were measured using ion chromatography.

[Occurrence, distribution and fate of antibiotics in sewage treatment plants].

Occurrence and distribution of eight selected antibiotics were screened at four sewage treatment plants (STPs). Individual concentrations in raw influent and final effluent from the four STPs ranged from 16 to 1987 ng x L(-1) and from 16 to 2054 ng x L(-1), respectively. The other analytes were only detected in a few samples with lower concentrations.

[Occurrence and seasonal changes of antibiotics in the Victoria Harbour and the Pearl River, South China].

The occurrence and seasonal changes of antibiotics in the Victoria Harbour and the Pearl River were studied using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry with multiple reaction monitoring (MRM). The results showed that the concentrations of antibiotics were mainly below the limit of quantification (LOQ) in the ambient marine water of Victoria Harbour. However, except for amoxicillin, all the target antibiotics were detected in the Pearl River during high (summer) and low (early spring) water seasons with the concentrations ranging from 13 to 69 ng x L(-1) and from 70 to 489 ng x L(-1), respectively.

Determination of selected antibiotics in the Victoria Harbour and the Pearl River, South China using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry.

Nine selected antibiotics in the Victoria Harbour of Hong Kong and the Pearl River at Guangzhou, South China, were analyzed using high-performance liquid chromatography-electrospray ionization tandem mass spectrometry. The results showed that the concentrations of antibiotics were mainly below the limit of quantification (LOQ) in the marine water of Victoria Harbour. However, except for amoxicillin, all of the antibiotics were detected in the Pearl River during high and low water seasons with the median concentrations ranging from 11 to 67 ng/L, and from 66 to 460 ng/L, respectively; and the concentrations in early spring were about 2-15 times higher than that in summer with clearer diurnal variations.