Zhou Qunfang

Preliminary investigation of a sensitive biomarker of organotin pollution in Chinese coastal aquatic environment and marine organisms

In nine batches of sea bivalves collected from Chinese coastal cities during the year of 2000 to 2002, a special sample named Mya arenaria was found to have strong ability of butyltin accumulation compared with the other sampled bivalves in the corresponding batches. Tributyltin compound was the predominant pollutant with the detection rate high up to 100%. Special high levels of g Sn/g were detected in some Mya arenaria samples. The results obtained showed that Mya arenaria was potentially a biomarker to indicate organotin pollution in coastal aquatic environment.

Direct Grignard pentylation of organotin-contaminated lard samples followed by capillary gas chromatography with flame photometric detection

During a recent investigation of the organotin-contaminated lard samples, a simple method was developed by direct Grignard pentylation of lard samples and capillary gas chromatography with flame photometric detection using quartz surface-induced tin emission. Using HP-I capillary column with temperature programming and FPD detector, pentylated tri-, di-, monometyltin, dioctyltin and Sn(IV) can be base-line separated and detected within 20 min. The analysis of pentylated tin compounds by GC-MS confirmed the existence of methyltins and inorganic tin in lard samples, which was agreeable with the results obtained by GC-FPD. The content of organotin compounds was calculated by internal standard method in which methyltripropyltin (MeSnPr3) acted as internal standard. The results showed that these samples were heavily contaminated with mg/g levers of dimethyltin, mu g/g levers of tri- and monomethyltin. Among them, one sample contained mg/g level of dioctyltin and one contained a little of inorganic form of Sn(IV). The recoveries of tri-, di- and monomethyltin were 95.7%, 105.5% and 105.7%, respectively

Headspace solid‐phase microextraction of butyltin species in sediments and their gas chromatographic determination

A rapid and solvent-free procedure for the simultaneous determination of mono-, di-, and tributyltin in sediments by headspace solid-phase microextraction (SPME) is described. The butyltin chlorides present in sediments were converted into their hydride forms by potassium tetrahydroborate prior to extraction. A quartz fiber coated with 100 mum film of polydimethylsiloxane (PDMS) is introduced into the headspace over the matrix to extract butyltin hydrides. After extraction, the fiber is directly inserted into the injector of the gas chromatograph (GC) for desorption, separation, and quantification. A laboratory modified flame photometric detector using quartz surface-induced tin emission (QSIL-FPD) was used throughout the experiment. The detection limits obtained with SPME-GC-QSIL-FPD for mono-, di-, and tributyltin are 8.8, 0.16, and 0.05 ng/g as Sn, respectively. The proposed method has been validated by analyzing standard reference material CRM-462, and successfully used for the determination of butyltin compounds in sediment collected from coastal areas of Hong Kong.

Vitellogenic responses of male Chinese loach (Misgurnus anguillicaudatus) exposed to the individual or binary mixtures of 17β-estradiol and nonylphenol

Male Chinese loaches were exposed to 17β-estradiol (E2) and nonylphenol (NP) both singly and in combination for 42 days using semi-static waterborne exposure system. Plasma vitellogenin (Vtg) was chosen as determining endpoint. The results demonstrated that 0.5 μg/L E2 could induce the enhancement of Vtg contents in male Chinese loaches after exposure for 21 days, which showed a time-related increasing manner; NP was also estrogenic to male Chines loach, and the vitellogenic responses showed in a time-and dose-related manner, which was less potent than that of E2. The binary mixtures of E2 and NP can significantly elicit the production of Vtg in male Chinese loaches, which was more potent than that of individual compounds, and Vtg induced in the binary mixture groups was higher than the summation of Vtg induced in the corresponding single-compound groups at the same concentration.