主题：【求助】EP5.4 重金属

METHOD C
方法C
Test solution. Place the prescribed quantity (not more than 2 g) of the substance to be examined in a silica crucible with 4 ml of a 250 g/l solution of magnesium sulphate R in dilute sulphuric acid R. Mix using a fine glass rod. Heat cautiously. If the mixture is liquid, evaporate gently to dryness on a water-bath. Progressively heat to ignition and continue heating until an almost white or at most grayish residue is obtained.
供试品溶液：取规定量的供试品（不得超过2g）于瓷坩埚内，加入4ml250g/L的硫酸镁的硫酸溶液，用玻璃棒搅拌混匀，缓慢加热，如果混合物是液体，在水浴锅上缓慢挥发至干。逐渐加热炽灼直到供试品的残留物变白或浅灰色。
Carry out the ignition at a temperature not exceeding 800 °C. Allow to cool. Moisten the residue with a few drops of dilute sulphuric acid R. Evaporate, ignite again and allow to cool.
将残渣在800°C以下炽灼，放冷，加入几滴稀硫酸将残渣润湿，加热使硫酸挥发，然后放冷。
The total period of ignition must not exceed 2 h. Take up the residue in 2 quantities, each of 5 ml, of dilute hydrochloric acid R. Add 0.1 ml of phenolphthalein solution R, then concentrated ammonia R until a pink colour is obtained.
总的炽灼时间不得过2h。将供试品炽灼残渣分成两份，每份加入5ml稀盐酸。加入0.1ml酚酞溶液和浓氨水至溶液显粉红色。
Cool, add glacial acetic acid R until the solution is decolorised and add 0.5 ml in excess. Filter if necessary and wash the filter. Dilute to 20 ml with water R.
冷却上述溶液，加入冰乙酸直至溶液无色并多加入0.5ml冰乙酸,必要时过滤并冲洗滤膜。用20ml水稀释。

Reference solution (standard). Prepare as described for the test solution, using the prescribed volume of lead standard solution (10 ppm Pb) R instead of the substance to be examined. To 10 ml of the solution obtained add 2 ml of the test solution.

标准对照溶液：制备方法同供试品溶液，使用规定体积的标准铅溶液（10ppm Pb）替代供试品进行试验。向10ml上述溶液加入2ml供试品溶液。

Monitor solution. Prepare as described for the test solution, adding to the substance to be examined the volume of lead standard solution (10 ppm Pb) R prescribed for preparation of the reference solution. To 10 ml of the solution obtained add 2 ml of the test solution.

控制溶液：按照供试品溶液制备方法进行试验，加入和供试品含铅量相同体积的标准铅溶液于对照溶液中。向10ml上述溶液加入2ml供试品溶液。

Blank solution. Amixture of 10ml of water R and 2 ml of the test solution.

空白溶液：取10ml水加入2ml供试品溶液。

--Monitor solution这句话的意思看不明白，是取供试品加入还是取和供试品相同含铅量的标准铅溶液加入？它们和reference solution是什么关系？谢谢！

To 12 ml of each solution, add 2 ml of buffer solution pH 3.5 R. Mix. Add 1.2 ml of thioacetamide reagent R. Mix immediately. Examine the solutions after 2 min. The test is invalid if the reference solution does not show a slight brown colour compared to the blank solution or if the monitor solution is not comparable with the reference solution. The substance to be examined complies with the test if any brown colour in the test solution is not more intense than that in the reference solution.

分别取12ml上述溶液，加入2mlpH3.5的缓冲溶液，混匀，加入1.2ml硫代乙酰胺试液。立刻混合，在2分钟内检查上述溶液。如果对照溶液不比空白溶液颜色深，或控制溶液比对照溶液没有同时操作，试验无效。

If the result is difficult to judge, filter the solutions through a membrane filter (pore size 3 μm; see Figure 2.4.8.-1, without the prefilter). Carry out the filtration slowly and uniformly, applying moderate and constant pressure to the piston. Compare the spots on the filters obtained with the different solutions.

如果结果难以判定，将供试品溶液用孔径3um的微孔滤膜过滤，见2.4.8.-1。缓慢的均一的过滤，过滤时的速度和压力保持不变，比较两种溶液在滤膜过滤后的色斑的颜色深浅。

--上面就是翻译的内容，麻烦帮忙分析一下，哪怕是某句不妥，谢谢！

Since tests prescribed in monographs have been developed using thioacetamide reagent R, if sodium sulphide solution R1 is used instead, it is necessary to include also for methods A and B a monitor solution, prepared from the quantity of the substance to be examined prescribed for the test, to which has been added the volume of lead standard solution prescribed for preparation of the reference solution.
各论中规定使用硫代乙酰胺试液，因此若要改用硫化钠溶液，无论是方法A还是方法B都应制备控制溶液。控制溶液的制法：取规定量的供试品，加入制备对照溶液所需（体积）的铅标准溶液。

monograph可以翻译成“各论”，即具体品种的药典标准。


The test is invalid if the monitor solution is not comparable with the reference solution.
最初我感觉comparable应该翻译成“一致”，是因为制备monitor solution所需供试品的量应该跟供试品溶液一致，所需标准铅溶液的量应该跟对照溶液一致。但是后来看了全文，这句话是在“结果判定”里的。上一句讲的是标准铅溶液颜色应该深于空白溶液，那这里判定检验是否有效的标准就不应该是是否加入了规定量的样品和标准铅溶液，而应该是颜色比较。还是应该翻译成：“若无法比较监控溶液的颜色，则检验无效。”

Test solution. Place the prescribed quantity (not more than 2 g) of the substance to be examined in a silica crucible with 4 ml of a 250 g/l solution of magnesium sulphate R in dilute sulphuric acid R. Mix using a fine glass rod. Heat cautiously. If the mixture is liquid, evaporate gently to dryness on a water-bath. Progressively heat to ignition and continue heating until an almost white or at most grayish residue is obtained.
供试品溶液：取规定量的供试品（不得超过2g）于瓷坩埚内，加入4ml250g/L的硫酸镁/稀硫酸溶液，用玻璃棒搅拌混匀，小心加热，如果混合物是液体，在水浴锅上缓慢挥发至干。逐渐加热炽灼直到供试品的残留物变白或浅灰色。

Carry out the ignition at a temperature not exceeding 800 °C. Allow to cool. Moisten the residue with a few drops of dilute sulphuric acid R. Evaporate, ignite again and allow to cool.
将残渣在不超过800°C的温度下炽灼，放冷，加入几滴稀硫酸将残渣润湿，蒸发，重新炽灼，然后放冷。

The total period of ignition must not exceed 2 h. Take up the residue in 2 quantities, each of 5 ml, of dilute hydrochloric acid R. Add 0.1 ml of phenolphthalein solution R, then concentrated ammonia R until a pink colour is obtained.
总的炽灼时间不得过2h。将供试品炽灼残渣溶于两份稀盐酸，每份5ml。加入0.1ml酚酞溶液，再加入浓氨水至溶液显粉红色。

Cool, add glacial acetic acid R until the solution is decolorised and add 0.5 ml in excess. Filter if necessary and wash the filter. Dilute to 20 ml with water R.
冷却上述溶液，加入冰乙酸直至溶液无色并多加入0.5ml冰乙酸,必要时过滤并冲洗滤器。用水稀释至20ml。

滤膜是filter membrane，这里用的应该是滤纸。

用20ml水稀释应该是Dilute with 20 ml of water.炽灼残渣已经加入了稀盐酸等溶液，稀释至20ml就不需要20ml的水了。

谢谢happy的这么快的回复，
“各论”的翻译感觉好多了，
上下文其实已经贴上去了，从1楼就是重金属的最开始部分，没有删节，
放上一个pdf的重金属内容，里面2.4.8开头部分就是1楼的内容了，不过因为我们试验需要的是方法C，所以方法A和B我都没有翻译过来。
如果有时间，麻烦看一下下面的全文，应该是没有遗漏。

EP5.4 重金属

Reference solution (standard). Prepare as described for the test solution, using the prescribed volume of lead standard solution (10 ppm Pb) R instead of the substance to be examined. To 10 ml of the solution obtained add 2 ml of the test solution.

标准对照溶液：制备方法同供试品溶液，使用规定体积的标准铅溶液（10ppm Pb）替代供试品进行制备。向10ml上述溶液加入2ml供试品溶液。

Monitor solution. Prepare as described for the test solution, adding to the substance to be examined the volume of lead standard solution (10 ppm Pb) R prescribed for preparation of the reference solution. To 10 ml of the solution obtained add 2 ml of the test solution.

控制溶液：按照供试品溶液制备方法进行制备，向供试品加入制备对照溶液所需体积的铅标准溶液（10 ppm）。取上述溶液10ml，加入2ml供试品溶液。

原文由 happyjyl 发表:
Test solution. Place the prescribed quantity (not more than 2 g) of the substance to be examined in a silica crucible with 4 ml of a 250 g/l solution of magnesium sulphate R in dilute sulphuric acid R. Mix using a fine glass rod. Heat cautiously. If the mixture is liquid, evaporate gently to dryness on a water-bath. Progressively heat to ignition and continue heating until an almost white or at most grayish residue is obtained.
供试品溶液：取规定量的供试品（不得超过2g）于瓷坩埚内，加入4ml250g/L的硫酸镁/稀硫酸溶液，用玻璃棒搅拌混匀，小心加热，如果混合物是液体，在水浴锅上缓慢挥发至干。逐渐加热炽灼直到供试品的残留物变白或浅灰色。

Carry out the ignition at a temperature not exceeding 800 °C. Allow to cool. Moisten the residue with a few drops of dilute sulphuric acid R. Evaporate, ignite again and allow to cool.
将残渣在不超过800°C的温度下炽灼，放冷，加入几滴稀硫酸将残渣润湿，蒸发，重新炽灼，然后放冷。

The total period of ignition must not exceed 2 h. Take up the residue in 2 quantities, each of 5 ml, of dilute hydrochloric acid R. Add 0.1 ml of phenolphthalein solution R, then concentrated ammonia R until a pink colour is obtained.
总的炽灼时间不得过2h。将供试品炽灼残渣分成两份，每份加入5ml稀盐酸。加入0.1ml酚酞溶液，再加入浓氨水至溶液显粉红色。

Cool, add glacial acetic acid R until the solution is decolorised and add 0.5 ml in excess. Filter if necessary and wash the filter. Dilute to 20 ml with water R.
冷却上述溶液，加入冰乙酸直至溶液无色并多加入0.5ml冰乙酸,必要时过滤并冲洗滤器。用水稀释至20ml。

滤膜是filter membrane，这里用的应该是滤纸。

用20ml水稀释应该是Dilute with 20 ml of water.炽灼残渣已经加入了稀盐酸等溶液，稀释至20ml就不需要20ml的水了。

重新看了一下happy的黑体字部分，
的确这样翻译更通顺。
滤纸和滤膜的区别之前没有注意到
dilute to 的确是稀释到的意思，呵呵，谢谢！

我从头到尾看看再给你回。呵呵，先洗头去，洗完慢慢看。

原文由 happyjyl 发表:
我从头到尾看看再给你回。呵呵，先洗头去，洗完慢慢看。

呵呵，谢谢啊~我已经看了3天了，实在看不懂了。
其实，里面最困惑我的已经感觉有些明朗了，
adding to the substance to be examined the volume of lead standard solution (10 ppm Pb) R prescribed for preparation of the reference solution.
这一长句话让我有点摸不着头脑，哈哈！
看了你的翻译，终于知道是什么意思了。
但是还是有些奇怪：既然是控制溶液，为什么还要向供试品中加入制备对照溶液所需体积的铅标准溶液，如果加入标准铅溶液，供试品需要称取多少呢？似乎里面没有提及。