SCHEDULE 10N.I.Sampling and analysis for parameters other than radioactive substances in water bottled and labelled as “spring water” and bottled drinking water

PART 2 N.I.Methods of analysis and performance characteristics

Table 1

Prescribed methods of analysis

1 Use the following method to make m-CP agar:

ParameterMethod
Clostridium perfringens (including spores)Membrane filtration followed by anaerobic incubation of the membrane on m-CP agar1 at 44 ±1ºC for 21± 3 hours. Count opaque yellow colonies that turn pink or red after exposure to ammonium hydroxide vapours for 20 to 30 seconds.
Coliform bacteriaBS-EN ISO 9308-1
Colony count 22ºC – enumeration of culturable microorganismsBS-EN ISO 6222
Colony count 37ºC – enumeration of culturable microorganismsBS-EN ISO 6222
EnterococciBS-EN ISO 7899-2
Escherichia coli (E. Coli)BS-EN ISO 9308-1
Pseudomonas aeruginosaBS-EN ISO 12780

Make a basal medium consisting of—

Tryptose30.0g
Yeast extract20.0g
Sucrose5.0g
L-cysteine hydrochloride1.0g
MgSO4.7H2O0.1g
Bromocresol purple40.0mg
Agar15.0g
Water1,000.0ml
Dissolve the ingredients of basal medium, adjust pH to 7.6 and autoclave at 121ºC for 15 minutes. Allow the medium to cool.
Dissolve—
D-cycloserine400.0mg
Polymyxine-B sulphate25.0mg
Indoxl-β-D-glucoside60.0mg
into 8ml sterile water and add it to the medium.
Add to the medium—
Filter-sterilised 0.5% phenolphthalein diphosphate solution20.0ml
Filter-sterilised 4.5% FeCl3.6H2O2.0ml
Table 2
Prescribed performance characteristics for methods of analysis

1 The method of analysis should determine total cyanide in all forms.

2 Oxidation should be carried out for 10 minutes at 100ºC under acid conditions using permanganate.

3 The performance characteristics apply to each individual pesticide and will depend on the pesticide concerned.

4 The performance characteristics apply to the individual substances specified at 25% of the parametric value in Table B in Part 2, Schedule 7.

5 The performance characteristics apply to the individual substance specified at 50% of the parametric value in Table B in Part 2, Schedule 7.

ParametersTrueness % of prescribed concentration or value specificationPrecision % of prescribed concentration or value or specificationLimit of detection % of prescribed concentration or value or specification
Aluminium101010
Ammonium101010
Antimony252525
Arsenic101010
Benzene252525
Benzo(a)pyrene252525
Boron101010
Bromate252525
Cadmium101010
Chloride101010
Chromium101010
Conductivity101010
Copper101010
Cyanide1101010
1,2-dichloroethane252510
Fluoride101010
Iron101010
Lead101010
Manganese101010
Mercury201020
Nickel101010
Nitrate101010
Nititre101010
Oxidisability2252510
Pesticides and related products3252525
Polycyclic aromatic hydrocarbons4252525
Selenium101010
Sodium101010
Sulphate101010
Tetrachloroethene5252510
Tetrachloromethane202020
Trichloroethene5252510
Trihalomethanes4252510