3. QUANTITATIVE ANALYSIS
3.定量分析
3.1. Organophosphorus insecticides. Examine by gas chromatography (2.2.28), using carbophenothion R as internal standard. It may be necessary to use a second internal standard to identify possible interference with the peak corresponding to carbophenothion.
3.1有机磷杀虫剂
气相色谱法(2.2.28),用三硫磷作为内标物,可能需要第二个内标物,以确定可能的三硫磷干扰峰
Test solution. Concentrate solution B in a current of helium for chromatography R almost to dryness and dilute to 100 μl with toluene R.
测试溶液:溶液B用氦气流干燥,并用甲苯稀释至100ul
Reference solution. Prepare at least three solutions in toluene R containing the insecticides to be determined and carbophenothion at concentrations suitable for plotting a calibration curve.
对照品溶液:至少准备包含三个待测定的杀虫剂甲苯溶液和三硫磷溶液,以制作标准曲线。
The chromatographic procedure may be carried out using:
在进行分析时可选用:
— a fused-silica column 30 m long and 0.32 mm in internal diameter the internal wall of which is covered with a layer 0.25 μm thick of poly (dimethyl) siloxane R,
毛细管柱,长30m,内径0.32mm,内径涂有0.25um厚的聚(二甲基)硅氧烷。
— hydrogen for chromatography R as the carrier gas. Other gases such as helium for chromatography R or nitrogen for chromatography R may also be used provided the
chromatography is suitably validated.
采用氢气作为载运气体,如采用氦气或氮气需要提供验证方法。
— a phosphorus-nitrogen flame-ionisation detector or a atomic emission spectrometry detector, maintaining the temperature of the column at 80 °C for 1 min, then raising it at a rate of 30 °C/min to 150 °C, maintaining at 150 °C for 3 min, then raising the temperature at a rate of 4 °C/min to 280 °C and maintaining at this temperature for 1 min, and maintaining the temperature of the injector port at 250 °C and that of the detector at 275 °C. Inject the chosen volume of each solution. When the chromatograms are recorded in the prescribed conditions, the relative retention times are approximately those listed in Table 2.8.13.-3. Calculate the content of each insecticide from the peak areas and the concentrations of the solutions.
磷氮火焰电离探测器或原子发射光谱仪。程序升温:柱温度初始80 ℃,保持1分钟后,以每分钟30 ℃升至150℃ ,保持3分钟;再以每分钟4 ℃ 升至280 ℃ ,保持1分钟。进样口及检测器温度应分别保持为250℃和275℃。
在上述分析条件下,注入适量的供试品溶液和对照品溶液,拟测定农药的相对保留时间见表2.8.13-3。测定峰面积,计算供试品溶液中拟测定农药的浓度,并计算样品中农药的含量。
3.2. Organochlorine and pyrethroid insecticides. Examine by gas chromatography (2.2.28), using carbophenothion as the internal standard. It may be necessary to use a second internal standard to identify possible interference with the peak corresponding to carbophenothion
3.2有机氯和拟除虫菊酯类农药
气相色谱( 2.2.28 ),用三硫磷作为内标物,可能需要第二个内标物,以确定可能的三硫磷干扰峰
Test solution. Concentrate solution C in a current of helium for chromatography R or oxygen-free nitrogen R almost to dryness and dilute to 500 μl with toluene R.
测试溶液:采用氦色谱或无氧铜氮浓缩溶液C至干燥,用甲苯稀释至500ul。
Reference solution. Prepare at least three solutions in toluene R containing the insecticides to be determined and carbophenothion at concentrations suitable for plotting a calibration curve.
对照品溶液:至少准备含有三个待测定的杀虫剂的甲苯溶液和三硫磷溶液,以制作标准曲线。
The chromatographic procedure may be carried out using:
在进行分析时可选用:
— a fused silica column 30 m long and 0.32 mm in internal diameter the internal wall of which is covered with a layer 0.25 μm thick of poly(dimethyl)(diphenyl)siloxane R,
毛细管色谱柱,长30m,内径0.32mm,内径覆盖0.25um厚的聚(二甲基)硅氧烷
— hydrogen for chromatography R as the carrier gas. Other gases such as helium for chromatography R or nitrogen for chromatography R may also be used, provided the
chromatography is suitably validated,
采用氢气作为载运气体,如采用氦气或氮气需要提供验证方法。
— an electron-capture detector,
电子捕获检测器
— a device allowing direct cold on-column injection, maintaining the temperature of the column at 80 °C for 1 min, then raising it at a rate of 30 °C/min to 150 °C, maintaining at 150 °C for 3 min, then raising the temperature at a rate of 4 °C/min to 280 °C and maintaining at this temperature for 1 min, and maintaining the temperature of the injector port at 250 °C and that of the detector at 275 °C. Inject the chosen volume of each solution. When the chromatograms are recorded in the prescribed conditions, the relative retention times are approximately those listed in Table 2.8.13.-4. Calculate the content of each insecticide from the peak areas and the concentrations of the solutions.
一个可以直接在冷柱上进样的设备。程序升温:柱温度初始80 ℃,保持1分钟后,以每分钟30 ℃升至150℃ ,保持3分钟;再以每分钟4 ℃ 升至280 ℃ ,保持1分钟。进样口及检测器温度应分别保持为250℃和275℃。
在上述分析条件下,注入适量的供试品溶液和对照品溶液,拟测定农药的相对保留时间见表2.8.13-4。测定峰面积,计算供试品溶液中拟测定农药的浓度,并计算样品中农药的含量。