HG/T 2416-1993 Determination of trace sulfur in photographic chemicals - Molecular absorption spectrophotometry
Some standard content:
Chemical Industry Standard of the People's Republic of China
HG/ T 2416 -93
Photographic Chemicals
Determination of Trace Amounts of Sulfur in Couplers
Molecular Absorption Spectrophotometry
Promulgated on March 22, 1993
Ministry of Chemical Industry of the People's Republic of China
Implementation on October 1, 1993
Chemical Industry Standard of the People's Republic of China
Photographic Chemicals
Determination of Trace Amounts of Sulfur in Couplers Molecular Absorption Spectrophotometry 1 Subject Content and Scope of Application
HG/ T 2416 — 93
This standard specifies the method for determining trace amounts of sulfur in couplers by the molecular absorption spectrophotometric method using potassium hydride reduction of mesitylene blue, including reagents and instruments. This standard is applicable to the determination of trace sulfur in colorants that can be reduced by potassium borohydride. The detection range is 14-200 mg/L (in terms of S,
2 Reference Standards
GB 602 Preparation of standard solutions for determination of impurities in chemical reagents GB603 Preparation of preparations and products used in test methods for chemical reagents GB6682 Specifications and test methods for water used in analytical laboratories GB/T 9721
General rules for molecular absorption spectrophotometry of chemical reagents (ultraviolet and visible light part) 3 Principle of the method
The trace sulfur in the color former is first reduced to sulfide with potassium borohydride, and the sulfide reacts with p-aminodimethylaniline hydrochloride to form a methylene blue compound, which is light blue and is determined by spectrophotometry. Reagents
The impurity standard solutions, preparations and products used in this standard are prepared in accordance with the provisions of GB602 and GB603. The laboratory water should meet the specifications of grade 3 water in GB6682. 4.1 Tetrahydrocannabinol: It needs to be purified by distillation. It should be purified before use. 4. 2 Potassium borohydride solution (30g/L): Weigh about 1.5g potassium borohydride, dissolve it with sodium hydroxide solution (8g/L) and dilute it to 50mL, shake it well, and prepare it before use.
4. 3 pH buffer solution (pH~ 4. 3): Weigh about 1. 0 g potassium iodide, 20. 0 g potassium bromide and 1. 0 g potassium dihydrogen phosphate (K,H,PO,·2H,O), dissolve in water and dilute to 1 000 mL, shake. This can be stored for one month. 4.4 Acetone: analytical grade,
4.5 Ferric chloride solution (30g/L): weigh about 3g ferric chloride (FeCl,·6H,O), dissolve in hydrochloric acid solution (1+1) and dilute to 100 mL, shake.
4.6 p-Aminodimethylamine hydrochloride solution (10 / L): weigh 1. 0 Polyaminodimethylaniline hydrochloride, accurate to 0.01g: Dissolve with hydrochloric acid solution (1+1) and dilute to 100nL. (If necessary, add activated carbon for decolorization) 5 Instruments and devices
5:1 General laboratory instruments,
Approved by the Ministry of Chemical Industry of the People's Republic of China on March 22, 1993, implemented on October 1, 1993
5.2 Analytical balance: Sugar content is 0.1mg.
HG/ T 2416 — 93
5.3 Glass core funnel: G5 or filter membrane with an average pore size of 2 to 5um.5.4 Spectrophotometer: in accordance with GB9721, 6 Determination steps
Weigh 1.0g sample, accurate to 0.01g, and put it into a 50mL dry stoppered conical flask, add 5mL tetrahydrofuran (4.1), cover the bottle stopper, shake until the sample is completely dissolved, add 2.0mL potassium hydride solution (4.2) with a pipette, stir, if the reaction is violent, open the stopper to release the generated hydrogen, then add 15mL pH buffer solution (4.3), and quickly add 1mL acetone (4.4), 1mL ferric chloride solution (4 .5) and 1mL of p-aminodimethylamine hydrochloride solution (4.6), shake thoroughly for about 1min to complete the reaction, then let it stand for 5min, filter it with a sand core funnel (5.3) at a wavelength of 670nm on a spectrophotometer, and measure its absorbance with a buffer solution of pH 4.3 as a reference. At the same time, do a blank test, and find the corresponding sulfur content from the working curve based on the measured absorbance to calculate the percentage of microdisk sulfur in the color former. 7 Drawing of the working curve
Respectively take 0.00, 0.10, 0.20, 0.40, 0.60, 0.80, and 1.00mL of sulfide impurity standard solution (1mL of the solution contains 5.0g of sulfur (S)) into each 50mL stoppered conical flask, and the following determination steps are the same as in 6. Finally, draw a working curve based on the measured absorbance and the known sulfur content. 8. Result calculation
The sulfur content (X%) in the colorant is calculated according to the following formula: X:
Where: n
(m, -m.) × 10
The sulfur content of the sample solution is obtained from the working curve, g: ma—The sulfur content of the blank reagent solution is obtained from the working curve, μg; one is the mass of the sample, g.
9. Method error
1~Precision
The same sample is measured no less than 7 times, and the relative standard deviation should not be greater than 5%. 9.2. Accuracy
Precision is expressed as recovery rate, and the recovery rate should be in the range of 95-105%. 10. Test report
The test report should include the following contents: x 100
． All information about the sample: batch number, date, time and location, instrument model used in the test: b, analysis results and expression methods; Www.bzxZ.net
, abnormal phenomena observed during the determination; d, any operation or optional test conditions not included in this standard, 11 Safety matters
Potassium hydroxide is a secondary water-burning item and is corrosive. It will burn the skin at high concentrations. It should be used strictly in accordance with relevant operating regulations. The equipment should be cleaned in time after use. 2
Additional instructions:
HG/T 2416-
This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China, and this standard is under the jurisdiction of the Photosensitive Material Technology Development Center of the Ministry of Chemical Industry. 93
This standard was drafted by Xiamen Photosensitive Materials Co., Ltd., and the Photosensitive Materials Technology Development Center of the Ministry of Chemical Industry participated in the drafting. The main drafters of this standard are Han Yifeng, Hao Hongying, Chen Yuehua, Jin Ting, and Ding Peiling. The People's Republic of China
Chemical Industry Standards
Photographic Chemicals
Determination of trace sulfur in couplers-Molecular absorption spectrophotometry HG/T 2416-93
Editorial Department of Chemical Industry Standards
(Standardization Institute of the Ministry of Chemical Industry)
Postal Code: 100013
Printing Standardization Institute of the Ministry of Chemical Industry
Copyright reserved. No reproduction allowed
Format 88×1230 1/16 Printing Sheet 516 Number of Words 30
1993 First edition in June 1993 First printing in June 1993 Qiu Shu! -300
Cost 1.90 yuan
26-91 1/0
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