RESUMO
Trimethoprim molecularly imprinted polymer (MIP) was prepared as the coating of stir bar sorptive extraction (SBSE) and applied to the trace analysis of trimethoprim and three sulfonamides in complex samples.The MIP-coating was about 21.5 μm thickness with the relative standard deviations (RSD) of 5.9％ (n=10).It was homogeneous and dense with good thermal and chemical stability.The extraction capability of the MIP-coating was 1.7 times over that of the non imprinted polymer (NIP) coating.The MIP coating exhibited selective adsorption ability to sulfonamides,triazines and methotrexate besides antibacterial synergists.The methods for the determination of trimethoprim and three sulfonamides by MIP-coated stir bar sorptive extraction coupled with HPLC were developed.It was successfully applied to the trace trimethoprim analysis in spiked urine and plasma samples.The linear range was 5 to 200 μg/L and the detection limit was 1.6 μg/L.The recoveries in urine and plasma samples were 84.5％ to 91.7％ with RSDs of 2.9％ -4.4％,71.9％ to 85.1％ with RSDs of 3.0％ -7.3％,respectively.The trimethoprim MIP-coated stir bar was also applied to the trace sulfonamides analysis in spiked milk sample.The linear range was 10-200 μg/L,the detection limit was within the range of 4.5-6.1 μg/L,and the recovery was 83.2％ - 110.2％ with RSDs of 4.1％ -8.0％.
RESUMO
A method for the determination of bisphenol A, octyphenol, nonylphenol in water samples was developed using stir bar sorptive extraction (SBSE) based on poly (vinylimidazole-divinylbenzene) monolithic material (SBSEM) combined with high performance liquid chromatography with diode array detection.To achieve the optimum extraction performance, several main extraction parameters, including extraction and desorption time, pH value and contents of inorganic salt in the sample matrix, were investigated.Under the optimized experimental conditions, the method showed good linearity and repeatability, low detection limits (S/N = 3) and quantification limits (S/N = 10) of the proposed method for the target compounds were achieved within the range of 0.13-0.66 and 0.44-2.19 μg/L, respectively.The extraction performance of SBSEM to the target compounds was also compared with commercial SBSE which used polydimethylsiloxane as coating.The proposed method was successfully applied to the determination of the target compounds in water samples.The recoveries of spiked target compounds in real samples ranged from 37.8%-101.1%.The results indicated that the developed method possessed advantages such as sensitivity, simplicity, low cost and high feasibility.
RESUMO
The chemical components of mainstream smoke were trapped by the artifical salvia. A novel method) for the analysis of the trapped chemical components was established using stir bar sorptive extraction(SBSE)) followed by a thermal desorption-gas chromatography-mass spectrometry(TD-GC-MS). The major) factors including desorption temperature, desorption time, cryofocusing temperature, extraction time and the addition of sodium chloride were studied. Under the optimized conditions, the average relative standard deviation(RSD) of peak areas of 44 components which were identified from the artifical saliva for 6 determinations was less than 10%, which showed the good repeatability of this method. The experiment result indicated that the SBSE-TD-GC-MS technique provided a powerful tool for the analysis of smoke components of some cigarette) trapped and dissolved in the saliva.