RESUMO
OBJECTIVE: To optimize the formulation of iodoform paste for root canal filling of deciduous teeth. METHODS: Using multi-indicators comprehensive scoring method, which takes the delicate degree, lubricity, difficulty of root canal filling, and difficulty of removal as performance indicators, the matrix type was screened, and the formulation of paste was optimized by orthogonal experimental design. The content of iodoform in the optimized paste was determined by UV spectrophotometry. RESULTS: Dimethicone was chosen as the paste matrix by comprehensive scoring of indicators. The results of orthogonal test showed that the ratio of iodoform and zinc oxide was the main factor affecting the performance of the paste, and the optimal formulation of paste was as follows: the ratio of iodoformto zinc oxide 3:7, clove oil 0.5%, and the ratio of powder to liquid 70:30.The linear range of the calibration curve for iodoform in the optimal paste was 48.75-146.22 μg·mL-1, A = 6.781 3C-0.051 6(r=0.999 6); and the average recovery rate was 99.83% (n=9). CONCLUSION: The optimal iodoform paste has a simple preparation, fine and smooth for root canal filling of deciduous teeth. The assay method is accurate and reliable for the quality control of iodoform paste.
RESUMO
<p><b>OBJECTIVE</b>To develop a urine pretreatment method of Solid Phase Extraction (SPE) for the quantitative determination of a number of aristolochic acids (AAs) and aristololactams (ALs) in rat urine.</p><p><b>METHOD</b>The HPLC peak area of AA-I , AA-II, AL-I and AL-II, and other sixteen AAs and ALs was chosen as evaluating index to study the extract results of five Solid Phase Extraction columns (Agilent C18/100 mg, Alltech HG18/100 mg, Alltech C18/100 mg, Alltech C18/300 mg and Agilent Phenyl/200 mg) comparatively. The influences of two washing solvents (water and 1% acetic acid-0.02% triethylamine solution) and seven eluting solvents (ether, acetone, chloroform, ethyl acetate, dichloromethane, methanol and acetonitrile) on extract results of AAs and ALs are comparatively studied with the extracting recoveries of AA-I , AA-II, AL-I and AL-II as indicators. The HPLC peak area of AA-I , AA-II, AL-I and AL-II, and other seven AAs and ALs with good separation being targets, several factors which affect extracting efficiency of analytes, including activating volume, cleansing volume, washing volume and eluting volume, are optimized by orthogonal design experiments with four factors at three levels.</p><p><b>RESULT</b>The established method of SPE is as follows: Agilent Phenyl SPE column of 200 mg, activating with 1.0 mL methanol, cleansing with 1 mL water, adding 1.0 mL rat urine sample, washing with 0.8 mL 1% acetic acid 0.02% triethylamine solution, and eluting with 3.0 mL methanol.</p><p><b>CONCLUSION</b>The established method of SPE is efficient, selective, simple and fast, and can be used as urine pretreatment method to analyze a variety of aristolochic acids and aristololactams in rat urine.</p>