吡柔比星中旋光度检测方案(旋光仪)

Application Note P-0004 Measurement of optical rotation of pirarubicin using sodium lamp andhalogen lamp Introduction An emission line of light source such as a sodium lamp or a mercury lamp is usually used to measurethe optical rotation of pharmaceutical products. However， the Japanese Pharmacopeia and the EuropeanPharmacopeia only mention the use of a sodium lamp as the light source. A polarimeter using a halogen lamp and a band pass filter (BPF) can also be used， as mentioned in theUnited States Pharmacopeia. However， the measurement error from the transmission property， that is thedifference between the center wavelength of the BPF and the wavelength of emission line， cannot beavoided. Herein， the optical rotation ofpirarubicin was measured using a sodium lamp and a halogen lamp， andthe measurement error between the results was evaluated. Keywords： Pirarubicin， Sodium lamp， Halogen lamp， Optical rotation，ORD spectrum Sample preparation： 10.00 mg of pirarubicin was dissolved in chloroform for final volume of 10 ml. System J-815 CD SpectrometerORDM-401 ORD attachment Parameters Cell pathlength：20 mm Temp.： 20℃ Bandwidth： 1nmData interval：00.2 nm Response： l sec Scan speed： 100 nm/min Wavelength： 700-560 nm Accumulation：1 Results At first， absorption and ORD spectra of pirarubicin were measured in the region of 700-560 nm toconfirm the wavelength dependence of the optical rotation (Fig. 1). The absorbance increased sharplybelow 600 nm and optical rotation increased gradually as a result of the Cotton effect. Fig. 1 Absorption and ORD spectra of pirarubicin The transmission spectrum of a BPF and the spectrum of the D-line of the sodium lamp， overlappedwith ORD spectrum are shown in Fig. 2. It is apparent to see the significant change of the specific rotationin the wavelength region within the BPF. Fig. 2ORD spectrum of pirarubicin， sodium lamp emission line and the transmission spectrum of the BPF Sample preparation： Identical sample for ORD measurement. System P-2000 PolarimeterPTC-262 Peltier thermostated cell holder Parameters Measurement temp.： 20°C Cell pathlength： 100 mm Wavelength： 589 nm (D-line of sodium and halogen lamp) Results Specific rotation of the same sample for the ORD measurement was measured using the polarimeter.When a sodium lamp is used as the light source， the result was [o] 20=+206.6 [deg'cm²dag-]. Thisvalue falls within the range stated in the Japanese Pharmacopeia.([a]20=+195~+215 [degcmdag])On the other hand， when using a halogen lamp， the specific rotation was just inside this range ([α]58920=+196.7 [deg'cmdag]). These two results clarify the difference in the optical rotations measured at thesame wavelength (589 nm) with different lamps. Table 1 Results of the optical and specific rotation measurements Light source Optical rotation [deg] Specific rotation [deg'cmdag 1 Sodium lamp +0.2066 [a]20：+206.6 Halogenlamp +0.1967 lal589 20：+196.7 copyrightOJASCO CorporationJASCO INTERNATIONAL CO.， LTD- Sennin-cho -chome， Hachioji， Tokyo JapanTel：+Fax：+ An emission line of light source such as a sodium lamp or a mercury lamp is usually used to measure the optical rotation of pharmaceutical products. However, the Japanese Pharmacopeia and the European Pharmacopeia only mention the use of a sodium lamp as the light source. A polarimeter using a halogen lamp and a band pass filter (BPF) can also be used, as mentioned in the United States Pharmacopeia. However, the measurement error from the transmission property, that is the difference between the center wavelength of the BPF and the wavelength of emission line, cannot be avoided. Herein, the optical rotation of pirarubicin was measured using a sodium lamp and a halogen lamp, and the measurement error between the results was evaluated.