주제어: Polyvinyl chloride 막; Bis-(2-ethylhexyl)phthalate; Malachite green; 고상추출 ABSTRACT. A new sensitive and selective spectrophotometric method for determination of trace amounts of cadmium using a polyvinyl chloride membrane containing bis-(2-ethylhexyl)phthalate as a solid phase extraction medium was investigated. Bis-(2-ethylhexyl)phthalate has used as a plasticizer. Cd(II) in an aqueous solution was trapped on the membrane in the form of colorful Cd (II)-I --MG complexes (which MG is malachite green) and the cadmium complex was concentrated in the membrane. The absorbance of the green membrane was measured at 629 nm using a spectrophotometer, and then, the concentration of the cadmium was calculated using a calibration curve, which expressed the relationship between the Cd(II) concentration and the membrane absorbance after coloring for 25 min. The calibration curve was linear in the range of 10-760 µgL and the relative standard deviations (RSD) were less than 4 % (n=5). The proposed method has been successfully applied to the determination of trace amounts of cadmium in the Tadjan River water sample (Sari-Iran), and the mean value of 28.7 µgL -1 was obtained.

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Introduction: Knowledge about the anatomy and morphology of the root canal system plays an important role in the prognosis of endodontic treatment and its success. Maxillary third molars with two distobuccal canals have been rarely reported. Herein, we report a maxillary third molar with 2 canals in the distobuccal root and describe its successful endodontic treatment. Case Presentation: Our patient was a 67-year-old man referred to a private endodontic clinic complaining of pain in his maxillary right third molar tooth. With the diagnosis of irreversible pulpitis, the tooth underwent root canal therapy, during which, after thorough negotiation of orifices, a second distobuccal canal was found. Cleaning and shaping were carried out and root canals were filled. A follow-up was scheduled to ensure a successful endodontic treatment. Conclusions: In this case, we did not use any adjunct diagnostic modality. We only found an additional canal by extending the access cavity and paying attention to landmarks by probing the fissures and grooves between the main orifices. However, it seems that use of new methods can enhance a successful treatment especially in the elderly patients.

Introduction: Knowledge about the anatomy and morphology of the root canal system plays an important role in the prognosis of endodontic treatment and its success. Maxillary 3rd molars with 2 distobuccal canals are rarely reported. Herein is the report of a 3rd maxillary molar with 2 canals in the distobuccal root and description of its successful endodontic treatment. Case Report: The patient was a 67-year-old male referred to a private endodontic clinic complaining of pain in his maxillary right 3rd molar tooth. With the diagnosis of irreversible pulpitis, the tooth underwent root canal therapy, during which, after thorough negotiation of orifices, a 2nd distobuccal canal was found. Cleaning and shaping were carried out and root canals were filled. A follow-up was scheduled to ensure a successful endodontic treatment. Conclusions: In the current case, no adjunct diagnostic modality was used. The additional canal was found only by extending the access cavity and paying attention to landmarks by probing the fissures and grooves between the main orifices, but it seems that use of new methods can enhance a successful treatment, especially in the elderly patients.