ABSTRACT
The ultrasound assisted emulsification microextraction [USAEME] method followed by inductively coupled plasma-atomic emission spectrometry [ICP-AES] was used for preconcentration and determination of bismuth [Bi], indium [In] and lead [Pb] hi the plant Azolla filiculoides Lam. Calix [4] pyrrole was used as a chelating agent and tetrachloroethylene was selected as extraction solvent. The main parameters of the USAEME method were optimized by using response surface methodology [RSM]. The optimal conditions were as follows: 130 microL for volume of extraction solvent, 4 min for sonication time, 6.75 [w/v%] for salt concentration, 890 mg/L for concentration of chelating agent and 7.5 for pH. The calibtaUou gxa
ABSTRACT
Polymerization of resin-based dental materials is not complete; and the release of unreacted monomers has undesirable effects on biocompatibility and integrity of material. The aim of this study was to evaluate the type and effect of dentin bonding agents, type of light curing unit, the distance between the tip of curing unit and surface of bonding agents on monomer leaching. This experimental study used 40 sound extracted teeth, with prepared cavities about 3x3x2 and 3x3x4 mm on the smooth surfaces. A self-etch bonding [Clearfil SE Bond Curary, Japan] and one etch and rinse [Scotch Bond multipurpose, USA] were applied on cavities according to the manufacturer's instruction. The bonding agents were cured with halogen [Optilux 501, Colten] and LED [Ultalume 2, Vivadent] lights. The samples were saved in pure methanol with 37°C for 24h. Liquids were studied with gas chromatography [GC] for detection of different monomers. Data were analyzed using 3-Way ANOVA and Independent T-tests. The type of bonding agent had significant effect on monomer release. Scotch Bond released more monomer than Clearfil SE Bond [P=0.001]. The effect of light curing unit on monomer leaching was not significant, but the samples of Scotch Bond with more distance released more monomer. Only HEMA monomer was detected from dentin bonding agents in this study. Scotch Bond released more HEMA than Clearfil SE Bond. Halogen and LED lights had no significant effect on monomer leaching. More distance between the tips of light causes less degree of polymerization
Subject(s)
Light-Curing of Dental AdhesivesABSTRACT
A new microextraction method named dispersive liquid-liquid microextraction [DLLME] for determination of chloroform in pool water and blood of swimmers after swimming is described. This method was performed based on coupling dispersive liquid-liquid microextraction [DLLME] with gas chromatography-mass spectrometry [GC-MS]. Methanol and trichloroethylenes were used as the disperser solvent and the extraction solvents, respectively. The volumes of these solvents were optimized for pool water by central composite design. The study involved three indoor swimming pools and nine swimmers. Chloroform concentration of pool water was 118-135 micro g L[-1] and of blood ranged from 1.26 to 1.66 micro g L[-1]. Indoor swimming pools are closed environments presenting detectable levels of trihalomethanes [THMs]. Chloroform [CHCl3] is the most represented THMs. Therefore, the presence of CHCl3 may be considered representative of the THMs. The new method DLLME was applied for determination of CHCl3 in pool water and blood of swimmers after swimming inside the indoor swimming pool. The method was optimized by experimental design. Chloroform concentrations in the specified pool waters were 135, 124, 118 micro g L[-1]