GB/T 18869-2019Determination of coliform in feeds (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 18869-2002 "Determination of coliforms in feed". Compared with GB/T 18869-2002, the main technical contents of this standard are revised as follows:

--- Revised the scope of application (see Chapter 1, Chapter 1 of the.2002 edition);

--- Added terms and definitions (see Chapter 3);

--- Modified the description of the principle (see Chapter 4, Chapter 3 of the.2002 edition);

--- Increased LST fermentation (see 8.3). This standard is proposed and managed by the National Feed Industry Standardization Technical Committee (SAC/TC76). This standard was drafted. Institute of Agricultural Quality Standards and Testing Technology, Chinese Academy of Agricultural Sciences [National Feed Quality Supervision and Inspection Center (Beijing)]. The main drafters of this standard. Li Lizhen, Liu Xiaolu, Li Sheng, Wang Wei. The previous versions of this standard were released as follows:

---GB/T 18869-2002. Determination of coliforms in feed

1 Scope

GB/T 18869-2019 is the Chinese national standard on determination of coliform in feeds, in the field of agriculture. The /T suffix marks it as a recommended standard: it is not compulsory by itself, but it becomes binding as soon as a contract, a tender or a customer specification calls it up - which in practice is how most foreign buyers meet it. It was issued on 4 June 2019 by the State Administration for Market Regulation; Standardization Administration of China, and has been in force since 1 January 2020. Classification: ICS 65.120, CCS B46. This page is published from the official record of the standard held by the Chinese standards administration: the identification, the dates, the classification and the issuing body are taken from there. The clause text, the tables and the numeric limits are in the document itself, which is delivered complete in English translation.

This standard specifies the method for determination of coliforms in feed. This standard applies to the determination of coliforms in feed and feed additives.

2 Normative references

The following documents are indispensable for the application of this document. For dated references, only dated versions apply to this article. Pieces. For undated references, the latest edition (including all amendments) applies to this document.

GB/T 6682 Analytical laboratory water specifications and test methods

3 Terms and definitions

The following definitions apply to this document.

3.1 Coliforms coliforms Aerobic or facultative anaerobic Gram-negative Bacillus-free bacilli capable of fermenting lactose to produce acid gas under certain culture conditions.

3.2 Most likely number of mostprobablenumber;MPN An indirect counting method based on Poisson distribution.

4 Principle

After the sample to be tested is diluted to an appropriate concentration and cultured, the statistics are applied according to the lowest dilution of the growth and the highest dilution of growth. Learn the probability theory to calculate the maximum possible number of coliforms in the sample to be tested.

5 Medium or material

Only reagents identified as analytically pure were used in the analysis unless otherwise stated.

5.1 Water. Meet the requirements of the third grade water in GB/T 6682.

5.2 Lactose bile salt fermentation medium. See Appendix A, A.1.

5.3 Ivy Blue Agar. See Appendix A, A.2.

5.4 Lactose fermentation medium. See Appendix A, A.3.

5.5 Gram stain. See Appendix A, A.4.

5.6 lauryl sulfate tryptone (LST) broth. see Appendix A, A.5.

5.7 Brilliantgreen lactosebile (BGLB) broth. See Appendix A, A.6.

5.8 Phosphate buffer. See A.7 in Appendix A.

5.9 Sterile saline. See Appendix A, A.8.