SN/T 4675.23-2016Determination of ammonium nitrogen in wine and grape juice for export--Continuous flow analysis(CFA)method (English PDF)

Foreword

SN/T 4675 "Methods for Quality and Safety of Exported Wines" is divided into 30 parts.

---SN/T 4675.1 Determination of glycerol in exported wines;

---SN/T 4675.2 Determination of 2,3-butanediol in exported wines by gas chromatography;

---SN/T 4675.3 Determination of the stable carbon isotope ratio of ethanol in exported wines;

---SN/T 4675.4 Determination of lactic acid in exported wines;

--- SN/T 4675.5 Determination of organic acids in exported wines by ion chromatography;

---SN/T 4675.6 Determination of glucose, fructose and sucrose in exported wines;

--- SN/T 4675.7 Determination of acetaldehyde in exported wines by gas chromatography-mass spectrometry;

--- SN/T 4675.8 Determination of 5-hydroxymethylfurfural in exported wines by liquid chromatography;

--- SN/T 4675.9 Determination of diethylene glycol in exported wines by gas chromatography-mass spectrometry;

---SN/T 4675.10 Determination of ochratoxin A in exported wines by liquid chromatography-mass spectrometry/mass spectrometry;

---SN/T 4675.11 Determination of seven anthocyanins in exported wines by ultra performance liquid chromatography;

---SN/T 4675.12 Determination of lysozyme in exported wines by liquid chromatography;

--- SN/T 4675.13 Determination of 2,4,6-trichlorotoluene residues in exported wines by gas chromatography-mass spectrometry;

---SN/T 4675.14 Determination of natamycin in exported wines by liquid chromatography-mass spectrometry/mass spectrometry;

---SN/T 4675.15 Determination of salicylic acid, dehydroacetic acid and p-chlorobenzoic acid in exported wines by liquid chromatography;

---SN/T 4675.16 Determination of fumaric acid in exported wines by liquid chromatography-mass spectrometry/mass spectrometry;

--- SN/T 4675.17 Determination of butyl tin content in exported wines by gas chromatography - mass spectrometry/mass spectrometry;

--- SN/T 4675.18 Determination of residual dithiocarbamate in exported wines.

---SN/T 4675.19 Determination of sodium, magnesium, potassium, calcium, chromium, manganese, iron, copper, zinc, arsenic, selenium, silver, cadmium and lead in exported wines;

---SN/T 4675.20 Determination of rare earth elements in exported wines by inductively coupled plasma mass spectrometry;

--- SN/T 4675.21 Determination of soluble inorganic salts in exported wines by ion chromatography;

---SN/T 4675.22 Determination of total sulfur dioxide in exported wines;

---SN/T 4675.23 Determination of ammonia nitrogen in exported wines and grape juices - Continuous flow analyzer method;

---SN/T 4675.24 Determination of the export wine Fulin-Shoka index spectrophotometer method;

--- SN/T 4675.25 Determination of the color of exported wine CIE1976 (L * a * b *) color space method;

---SN/T 4675.26 Determination of turbidity of exported wines by scattered light method;

---SN/T 4675.27 Determination of alkaline ash in exported wines;

---SN/T 4675.28 Counting bacteria, mold and yeast for exporting wine;

---SN/T 4675.29 Real-time fluorescent PCR method for wine yeast test in exported wine;

---SN/T 4675.30 In the wine, the Bayesian yeast test real-time fluorescent PCR method.

This part is the 23rd part of SN/T 4675.

This part is drafted in accordance with the rules given in GB/T 1.1-2009.

This part is proposed and managed by the National Certification and Accreditation Administration.

This section drafted by. Beijing Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China, Shanghai Entry and Exit Inspection and Quarantine Bureau, Guangdong Entry-Exit Inspection and Quarantine Bureau of the People's Republic of China.

1 Scope

This part of SN/T 4675 specifies the method for the determination of continuous flow analyzers for the export of ammonia and nitrogen in grape juice.

This section applies to the determination of ammonia nitrogen in wine and grape juice.

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 Method summary

The sample and reagent enter the chemical reaction module under the push of the peristaltic pump, and continuously flow in the closed pipeline, and the bubble is arranged at a certain interval.

Separated by law. In an alkaline medium, the ammonia and ammonium ions in the sample react with the hypochlorite released from the sodium dichloroisocyanurate solution to form chlorine.

amine. Under the condition of 40 ° C and sodium nitroferricyanide, chloramine reacts with salicylate to form a blue-green compound at 660 nm.

The absorbance was measured at the strength, and the external standard method was used for quantification.

Refer to the work flow chart, as shown in Figure 1.

Fig.1 Flow path diagram for determination of ammonia nitrogen content in wine and grape juice by continuous flow analysis

4 Reagents and materials

Unless otherwise stated, all reagents were of analytical grade and the water was secondary water as specified in GB/T 6682.

4.1 Ammonium chloride (NH4Cl). excellent grade, dried at 105 ° C ± 1 ° C constant weight, stored in a desiccator.

4.2 Ethanol (C2H5OH).