企业为什么要求纯化水的内控电导率低于2μS/cm ？

wanda999

2010版GMP纯化水20摄氏度时小于4.2μS/cm,25摄氏度时小于5.1μS/cm，企业为什么要求纯化水的内控电导率低于2μS/cm，具体依据是什么！谢谢！

冷血无情

你也说了，是企业内控，你们就是定成0.5也没人说什么

工作QQ

Procedure
Stage 1
Stage 1 is intended for online measurement or may be performed offline in a suitable container.
1. Determine the temperature of the water and the conductivity of the water using a nontemperature-compensated conductivity reading.
2. Using the Stage 1—Temperature and Conductivity Requirements table, find the temperature value that is not greater than the measured temperature, i.e., the next lower temperature. The corresponding conductivity value on this table is the limit. [Note—Do not interpolate. ]
3. If the measured conductivity is not greater than the table value, the water meets the requirements of the test for conductivity. If the conductivity is higher than the table value, proceed with Stage 2.
Stage 1—Temperature and Conductivity Requirements
(for nontemperature-compensated conductivity measurements only)
Temperature        Conductivity Requirement (μS/cm)
0        0.6
5        0.8
10        0.9
15        1.0
20        1.1
25        1.3
30        1.4
35        1.5
40        1.7
45        1.8
50        1.9
55        2.1
60        2.2
65        2.4
70        2.5
75        2.7
80        2.7
85        2.7
90        2.7
95        2.9
100        3.1
Stage 2
4. Transfer a sufficient amount of water (100 mL or more) to a suitable container, and stir the test specimen. Adjust the temperature, if necessary, and, while maintaining it at 25 ± 1, begin vigorously agitating the test specimen while periodically observing the conductivity. When the change in conductivity (due to uptake of atmospheric carbon dioxide) is less than a net of 0.1 μS/cm per 5 minutes, note the conductivity.
5. If the conductivity is not greater than 2.1 μS/cm, the water meets the requirements of the test for conductivity. If the conductivity is greater than 2.1 μS/cm, proceed with Stage 3.
Stage 3
6. Perform this test within approximately 5 minutes of the conductivity determination in Step 5, while maintaining the sample temperature at 25 ± 1. Add a saturated potassium chloride solution to the same water sample (0.3 mL per 100 mL of the test specimen), and determine the pH to the nearest 0.1 pH unit, as directed under pH 791.

Stage 3

6. Perform this test within approximately 5 minutes of the conductivity determination in Step 5, while maintaining the sample temperature at 25 ± 1. Add a saturated potassium chloride solution to the same water sample (0.3 mL per 100 mL of the test specimen), and determine the pH to the nearest 0.1 pH unit, as directed under pH 791.

7. Referring to the Stage 3—pH and Conductivity Requirements table, determine the conductivity limit at the measured pH value. If the measured conductivity in Step 4 is not greater than the conductivity requirements for the pH determined in Step 6, the water meets the requirements of the test for conductivity. If either the measured conductivity is greater than this value or the pH is outside the range of 5.0 to 7.0, the water does not meet the requirements of the test for conductivity.

Stage 3—pH and Conductivity Requirements
(for atmosphere- and temperature-equilibrated samples only)

pH

Conductivity Requirement (μS/cm)

5.0

4.7

5.1

4.1

5.2

3.6

5.3

3.3

5.4

3.0

5.5

2.8

5.6

2.6

5.7

2.5

5.8

2.4

5.9

2.4

6.0

2.4

6.1

2.4

6.2

2.5

6.3

2.4

6.4

2.3

6.5

2.2

6.6

2.1

6.7

2.6

6.8

3.1

6.9

3.8

7.0

4.6

STERILE WATER

The procedure and test limits are intended for Sterile Purified Water, Sterile Water for Injection, Sterile Water for Inhalation, and Sterile Water for Irrigation, and any other monographs which specify this section. The sterile waters are derived from Purified Water or Water for Injection, and therefore have been determined to be compliant with the Bulk Water requirements before being stored in the container. The specification provided represents the maximum allowable conductivity value, taking into consideration the limitation of the measurement method and reasonable container leaching. Such specification and the sampling volume choices should be defined and validated on the basis of the intended purpose of the water.

Procedure

Transfer a sufficient amount of water to a suitable container, and stir the test specimen. Adjust the temperature, if necessary, and, while maintaining it at 25 ± 1, begin vigorously agitating the test specimen while periodically observing the conductivity. When the change in conductivity (due to uptake of ambient carbon dioxide) is less than a net of 0.1 μS/cm per 5 minutes, note the conductivity.

For containers with a nominal volume of 10 mL or less, if the conductivity is not greater than 25 μS/cm, the water meets the requirements. For containers with a nominal volume greater than 10 mL, if the conductivity is not greater than 5 μS/cm, the water meets the requirements.

Auxiliary Information— Please check for your question in the FAQs before contacting USP.

Topic/Question

Contact

Expert Committee

General Chapter

Antonio Hernandez-Cardoso, M.Sc.
Senior Scientific Liaison
1-301-816-8308

(GCCA2010) General Chapters - Chemical Analysis

USP35–NF30 Page 267
Pharmacopeial Forum: Volume No. 35(5) Page 1226

马甲

内控标准，一般来自于设备厂家根据设备运行经验给出的建议值

wgt-王

我们25摄氏度时的警戒线为3.5μS/cm，纠偏线为4.5μS/cm！！！！

wanda999

冷血无情 发表于 2015-10-5 15:19
你也说了，是企业内控，你们就是定成0.5也没人说什么

对不起，新手想看看鸡蛋是什么，不想砸出去了，收不回来。我赞同您的观点。

冷血无情

wanda999 发表于 2015-10-5 15:29
对不起，新手想看看鸡蛋是什么，不想砸出去了，收不回来。我赞同您的观点。

好吧，一般公司有的定50的警戒，70的纠偏，有的可能警戒限检测结果经常超限，可能会把警戒标准升高的，比如70的警戒，80的纠偏等

补充内容 (2015-10-9 12:17):
都怎么个意思，都想看看鸡蛋啥样是么，不知道这是对人的不尊重么，52:1的比例就这么几天就变成了52:4，都是闲的吧

nunqing

05版本的药典是要求2的。

石头968

内控标准，基于设备本身的控制能力和行业认可的技术标准。
也就是内控标准要求在技术标准之上、设备又能很稳定地控制在这个范围内。

chenlili1968

这是内控标准，根据设备运行经验给出的建议值 。

DY11027

看设备性能給的，我公司给的还0.5呢，约小说明设备越好， 而控制越严自然对生产工艺越好。再说这个超标了就一偏差，不影响产品放行的

雪锋

多种因素，问下人你们定标准的人。

叶非

你们企业为什么这么定，似乎应该问那个制定者，而不是在这里！另外，2010年版GMP在哪里订了纯化水的标准，请指教！

伟的

2.0是依据美国药典离线电导率不大于2.1制定的。

BOBO1899

这个又不是必需的。根据你自己公司当地的水质状况来定就行了

Trevor

其他的不知道，2.0是根据USP药典的规定来的。

尼采

就是公司内部多年的经验所得

工作QQ

伟的 发表于 2015-10-6 16:58
2.0是依据美国药典离线电导率不大于2.1制定的。

强！查下美国药典验证下。

毛毛球

uiofer 发表于 2015-10-6 10:58
你们企业为什么这么定，似乎应该问那个制定者，而不是在这里！另外，2010年版GMP在哪里订了纯化水的标准， ...

药典

ptq518

伟的 发表于 2015-10-6 16:58
2.0是依据美国药典离线电导率不大于2.1制定的。

正解，但这是“三步法”测定的每二步标准（第一步标准是1.3呵呵）