【原创】EP 2.2.24. 吸收光谱测定法，红外 翻译

B. Disc
Triturate 1-2 mg of the substance to be examined with 300-400 mg, unless otherwise specified, of finely powdered and dried potassium bromide R or potassium chloride R. These quantities are usually sufficient to give a disc of 10-15 mm diameter and a spectrum of suitable intensity. If the substance is a hydrochloride, it is recommended to use potassium chloride R. Carefully grind the mixture, spread it uniformly in a suitable die, and submit it to a pressure of about 800 MPa (8 t•cm-2). For substances that are unstable under normal atmospheric conditions or are hygroscopic, the disc is pressed in vacuo. Several factors may cause the formation of faulty discs, such as insufficient or excessive grinding, humidity or other impurities in the dispersion medium or an insufficient reduction of particle size. A disc is rejected if visual examination shows lack of uniform transparency or when transmittance at about 2000 cm-1 (5µm) in the absence of a specific absorption band is less than 60 per cent without compensation, unless otherwise prescribed.
B．压片法
除另有规定外，将1~2mg被测物质与300~400mg已干燥过的KBr或者KCl细粉混合研磨。通常这个量可以做出一个直径10~15mm、能产生合适强度光谱的圆片。如果被测物质为盐酸化物，建议用KCl。仔细研磨混合物，均匀地转移到合适的模具中，然后在800Mpa（8t•cm-2）压力下压片。对于在常压下不稳定或易吸潮的物质，应在真空下压片。以下几个因素可能造成压片不当，比如研磨不充分或者过度研磨，湿度、分散介质中引进的其他杂质，或者粒度不够小等。除另有规定外，如果肉眼检查显示不是均匀透明的，或者在没有特殊吸收谱带的约2000cm-1（5µm）处的透射比在未补偿的情况下少于60%，这样的片子是不合格的。
FOR RECORDING BY DIFFUSE REFLECTANCE
以漫反射系数记录
Solids. Triturate a mixture of the substance to be examined with finely powdered and dried potassium bromide R or potassium chloride R. Use a mixture containing approximately 5 per cent of the substance, unless otherwise specified. Grind the mixture, place it in a sample cup and examine the reflectance spectrum.
固体：将供试品与干燥过的KBr或者KCl细粉混合研磨。除另有规定外，混合物中约含5%被测物。研磨混合物，将其转移到一个样品杯中，检测其反射光谱。
The spectrum of the sample in absorbance mode may be obtained after mathematical treatment of the spectra by the Kubelka-Munk function.
用Kubelka-Munk光谱函数对图谱进行二数学处理可得到样品的吸收光谱。
FOR RECORDING BY ATTENUATED TOTAL REFLECTION
以衰减全反射（ATR）形式记录
Attenuated total reflection (including multiple reflection) involves light being reflected internally by a transmitting medium, typically for a number of reflections. However, several accessories exist where only one reflection occurs. Prepare the substance as follows. Place the substance to be examined in close contact with an internal reflection element (IRE) such as diamond, germanium, zinc selenide, thallium bromide-thallium iodide (KRS-5) or another suitable material of high refractive index. Ensure close and uniform contact between the substance and the whole crystal surface of the internal reflection element, either by applying pressure or by dissolving the substance in an appropriate solvent, then covering the IRE with the obtained solution and evaporating to dryness. Examine the attenuated total reflectance (ATR) spectrum.
衰减全反射（包括多次反射）涉及到被透射介质从内部反射的光，特别是多次反射时。然而，产生一个反射光的有多个光谱附件集。按照如下要求准备样品：将供试品紧贴内反射元件（IRE），如钻石、硒化锌、溴碘化铊（KRS-5）、或其他高折光率的合适材料。通过施加压力，或将样品溶解在合适的溶剂中，然后涂在IRE上，挥发至干，以确保供试品与整个内反射元件（IRE）晶体表面紧密、均匀接触。检测ATR光谱。
IDENTIFICATION USING REFERENCE SUBSTANCES
用对照物质定性
Prepare the substance to be examined and the reference substance by the same procedure and record the spectra between 4000-650 cm-1 (2.5-15.4µm) under the same operational conditions. The transmission minima (absorption maxima) in the spectrum obtained with the substance to be examined correspond in position and relative size to those in the spectrum obtained with the reference substance (CRS).
用同样的方法制备供试品与对照品，在同样的操作条件下记录波数为4000 ~ 650cm-1范围（波长2.5~15.4µm）的光谱。被测物质图谱的最小透光率（最大吸光度）的位置和相对大小与对照品（CRS）光谱的一致。
When the spectra recorded in the solid state show differences in the positions of the transmission minima (absorption maxima), treat the substance to be examined and the reference substance in the same manner so that they crystallise or are produced in the same form, or proceed as prescribed in the monograph, then record the spectra.
当固态供试品光谱中的最小透光率（最大吸光度）的位置与对照品图谱的有差异时，用相同的方法处理供试品和对照品以使其有晶型，或变成同样的形态结构，或者按照各论项下要求处理，然后记录光谱。

IDENTIFICATION USING REFERENCE SPECTRA
用对照光谱定性
Control of resolution performance. For instruments having a monochromator, record the spectrum of a polystyrene film approximately 35µm in thickness. The difference x (see Figure 2.2.24.-1) between the percentage transmittance at the transmission maximum A at 2870 cm-1 (3.48µm) and that at the transmission minimum B at 2849.5 cm-1 (3.51µm) must be greater than 18. The difference y between the percentage transmittance at the transmission maximum C at 1589 cm-1 (6.29µm) and that at the transmission minimum D at 1583 cm-1 (6.32µm) must be greater than 10.
分辨率控制对于带有单色器的仪器，记录厚约35µm的聚苯乙烯膜的光谱。在2870cm-1（3.48µm）的最大透光率A与在2849.5cm-1（3.51µm）的最小透光率B之间的百分透射比之差x（见图2.2.24.-1）必须大于18。在1589cm-1（6.29µm）的最大透光率C和1583cm-1（6.32µm）的最小透光率D之间的百分透射比之差y必须大于10。

Figure 2.2.24.-1. - Typical spectrum of polystyrene used toverify the resolution performance
图2.2.24-1—用聚苯乙烯验证分辨率的典型图谱
For Fourier-transform instruments, use suitable instrument resolution with the appropriate apodisation prescribed by the manufacturer. The resolution is checked by suitable means, for example by recording the spectrum of a polystyrene film approximately 35 pm in thickness. The difference between the absorbances at the absorption minimum at 2870 cm-1 and the absorption maximum at 2849.5 cm-1 is greater than 0.33. The difference between the absorbances at the absorption minimum at 1589 cm-1 and the absorption maximum at 1583 cm-I is greater than 0.08.
对于傅立叶变换仪，用厂商规定的适当的变迹法，选择合适的仪器分辨率。用合适的方法选择分辨率，比如，通过记录厚约35um的聚苯乙烯膜的光谱。在2870cm-1的最小吸光率和2849.5cm-1的最大吸光率之间的差必须大于0.33。在1589cm-1的最小吸光率和1583cm-1的最大吸光率之间的差别必须大于0.08。
Verification of the wave-number scale. The wave-number scale may be verified using a polystyrene film, which has transmission minima (absorption maxima) at the wave numbers (in cm-l) shown in Table 2.2.24.-1.
波数标度验证：波数标度可以用聚苯乙烯膜进行验证，其最小透光率（最大吸光率）所在波数（单位：cm-l）在表2.2.24-1.中给出。
Table 2.2.24.-1. – Transmission minima and acceptable tolerances of a polystyrene film
表2.2.24-1.-- 聚苯乙烯膜的最小透光率及可接受误差范围
Transmission minima (cm-1)
最小透光率(cm-1)    Acceptable tolerance (cm-1) 可接受误差(cm-1)
    Monochromator instruments
单色仪    Fourier-transform instruments
傅立叶变换仪
3060.0    ±1.5    ±1.0
2849.5    ±2.0    ±1.0
1942.9    ±1.5    ±1.0
1601.2    ±1.0    ±1.0
1583.0    ±1.0    ±1.0
1154.5    ±1.0    ±1.0
1028.3    ±1.0    ±1.0
Method. Prepare the substance to be examined according to the instructions accompanying the reference spectrum/reference substance. Using the operating conditions that were used to obtain the reference spectrum, which will usually be the same as those for verifying the resolution performance, record the spectrum of the substance to be examined.
方法：按照说明书和对照图谱/对照品处理供试品。采用对照图谱的操作条件记录被测物质的图谱，通常和验证分辨率的方法一样，。
The positions and the relative sizes of the bands in the spectrum of the substance to be examined and the reference spectrum are concordant in the 2 spectra.
供试品谱带的位置和相对大小与对照图谱是一致的。
Compensation for water vapour and atmospheric carbon dioxide. For Fourier-transform instruments, spectral interference from water vapour and carbon dioxide is compensated using suitable algorithms according to the manufacturer's instructions. Alternatively, spectra can be acquired using suitable purged instruments or ensuring that sample and background single beam spectra are acquired under exactly the same conditions.
水蒸气和大气中CO2的补偿：对于傅立叶变换仪器，来自水蒸气和CO2的光谱干扰要根据生产商的说明，用合适的运算法则进行补偿。作为替代选择，可以选用合适的净化仪器来获得光谱，或者确保样品和背景单一光谱是在完全相同条件下获得的。

红色部分不是很理解，欢迎指点