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WS/T 553-2017: Method for Vitamin A deficiency screening
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Method for Vitamin A deficiency screening
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WS/T 553-2017
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Basic data | Standard ID | WS/T 553-2017 (WS/T553-2017) | | Description (Translated English) | Method for Vitamin A deficiency screening | | Sector / Industry | Health Industry Standard (Recommended) | | Classification of Chinese Standard | C55 | | Word Count Estimation | 7,775 | | Date of Issue | 2017-08-01 | | Date of Implementation | 2018-02-01 | | Regulation (derived from) | State-Health-Communication (2017) 10 | | Issuing agency(ies) | National Health and Family Planning Commission of the People's Republic of China | WS/T 553-2017: Method for Vitamin A deficiency screening---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Method for Vitamin A deficiency screening
ICS 11.020
C 55
WS
People's Republic of China Health Industry Standard
Screening methods for population vitamin A deficiency
2017-08-01 released
2018-02-01 implementation
Issued by the National Health and Family Planning Commission of the People's Republic of China
Foreword
This standard was drafted in accordance with the rules given in GB/T 1.1-2009.
The main drafting organizations of this standard. Institute of Nutrition and Health, Chinese Center for Disease Control and Prevention, Capital Institute of Pediatrics, Peking University Health Science Center
Public Health College, Zhejiang Provincial Center for Disease Control and Prevention.
The main drafters of this standard. Huo Junsheng, Pu Wei, Ding Gangqiang, Sun Jing, Huang Jian, Wang Lijuan, Tang Yanbin, Chen Di, Li Jin, Gao Jie,
Zhang Ting, Lin Xiaoming, Li Keji, Zhang Ronghua.
Screening methods for population vitamin A deficiency
1 Scope
This standard specifies the indicators and detection methods for the screening of the population for vitamin A deficiency and the corresponding thresholds for vitamin A deficiency.
This standard applies to the determination of vitamin A deficiency in the population. The clinical diagnosis of individual vitamin A deficiency needs to be combined with clinical practice.
2 Normative references
The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article
Pieces. For undated references, the latest version (including all amendments) applies to this document.
WS/T 225 Collection and processing of blood samples for clinical chemistry tests
3 Terms and definitions
The following terms and definitions apply to this document.
3.1
Vitamin A vitamin A
Retinol
Generic term for Pionone derivatives. A fat-soluble vitamin. There are two kinds of vitamin A1 and vitamin A2
3.2
Vitamin A deficiency
The level of vitamin A in the human body is not enough to maintain normal physiological functions, and the level of retinol in the serum (plasma) of children (6 years old and below) is lower than
0.35µmol/L, less than 0.70µmol/L for children over 6 years old and adults, and pathological changes of eyes and skin may occur.
3.3
Marginal vitamin A deficiency
The level of vitamin A in the human body can maintain normal physiological functions, but the level of retinol in the serum (plasma) increases after vitamin A supplementation.
4 Criteria for borderline deficiency and deficiency of vitamin A in the population
The content of retinol per unit volume of serum (plasma) is used as a screening indicator for vitamin A deficiency. When the measured serum (plasma) retinol contains
When the amount is less than the corresponding reference value, it is judged as the corresponding borderline deficiency or deficiency of vitamin A. See Table 1 for the judgment index and judgment threshold.
Note. Conversion factor of 1mol retinol = 286.45 g retinol.
5 Criteria for determining the level of public vitamin A deficiency in the population
In the assessed population of 1 year and older, calculate the proportion of people with serum (plasma) retinol content < 0.70 µmol/L, according to vitamin A
The lack of public health problem criteria determines the severity of the public health problem of vitamin A deficiency in this population. Determine the problem level
And the judgment value is shown in Table 2.
6 Determination of serum (plasma) vitamin A
Measure according to the serum (plasma) retinol determination method specified in Appendix A-high performance liquid chromatography (HPLC).
AA
Appendix A
(Normative appendix)
Serum (plasma) retinol determination method-high performance liquid chromatography (HPLC)
A.1 Principle
Serum (plasma) was added with internal standard retinol acetate, extracted with n-hexane, and separated by high performance liquid chromatography C18 reverse column
After separation, it is quantitatively detected by UV detector.
A.2 Reagents and materials
Unless otherwise specified, all chromatographic reagents and distilled water or equivalent purity water (H2O) are used in this method.
A.2.1 Anhydrous ethanol (C2H6O).
A.2.2 Methanol (CH4O).
A.2.3 n-hexane (C6H14).
A.2.4 Nitric acid (HNO3).
A.2.5 Standard Retinol (C20H30O).
A.2.6 Standard Retinol Acetate (C22H32O2).
A.2.7 High-purity nitrogen (N2).
A.3 Instruments
A.3.1 High performance liquid chromatograph with UV spectrophotometer.
A.3.2 Nitrogen blowing instrument.
A.3.3 Centrifuge. speed ≥5000 r/min.
A.3.4 Balance. Sensitivity is 0.1 mg.
A.3.5 Ultraviolet spectrophotometer.
A.4 Sample collection and storage
Refer to WS/T 225 for venous blood collection, serum (plasma) separation and blood sample storage.
Note. The collection and pre-processing of blood samples must be carried out in a dark or red light environment to avoid changes in the content of retinol in the blood samples.
A.5 Analysis steps
A.5.1 Preparation of retinol standard stock solution
A.5.1.1 Take a certain amount of standard retinol, put it into a 10 mL volumetric flask, dissolve it in a small amount of absolute ethanol, and dilute it to 10 mL.
Into retinol standard stock solution.
A.5.1.2 Draw 100 µL of the retinol standard stock solution, place it in a 10 mL volumetric flask, and add absolute ethanol to make the volume to 10 mL (repeat twice).
A.5.1.3 Use an ultraviolet spectrophotometer to detect the content of the retinol standard stock solution at a wavelength of 325 nm. The blank reagent is anhydrous ethyl acetate.
alcohol. The specific absorption coefficient was used to calculate the concentration of retinol in the standard stock solution.
A.5.1.4 The retinol content in the stock solution is calculated according to formula (A.1).
A.5.2 Preparation of retinol acetate internal standard
A.5.2.1 Using a 0.1 mg balance, accurately weigh 82.0 mg of the standard retinol acetate, and pour it into a 10 mL volumetric flask.
After the alcohol is fully dissolved, the volume is adjusted to 10 mL, and the concentrated solution of retinol acetate internal standard is prepared.
A.5.2.2 Use a high performance liquid chromatograph to detect the peak area of the concentrated solution of retinol acetate internal standard at 325 nm, and dilute it with absolute ethanol.
Release to a working solution of retinol acetate internal standard at a concentration of approximately 6 µg/mL.
A.5.3 Drawing of standard curve
A.5.3.1 Preparation of retinol standard curve
Respectively draw the calibrated retinol standard stock solution into a 10 mL brown volumetric flask, and then add an equal volume of retinol acetate internal standard to work
Place the solution in a brown volumetric flask and dilute to the mark with absolute ethanol so that the concentration of the retinol standard solution is 1.00 µg/mL, 0.50 µg/mL,
0.30 µg/mL, 0.20 µg/mL, 0.10 µg/mL and 0.05 µg/mL. To be tested, get on the machine.
Note. All standard products are stored in a -20˚C low-temperature refrigerator.
A.5.3.2 Reference conditions for high performance liquid chromatography
The reference conditions of HPLC should meet the following requirements.
--Pre-column. 4.0 mm×4.5 cm, 10 µm.
--Analytical column. C18 column, 4.6 mm×25.0 cm, 5 µm.
--Mobile phase. methanol.water=98.2.Mix the mobile phase thoroughly before use, and degas before use.
--Flow rate. 1 mL/min.
--Detection wavelength. 325 nm.
--Column temperature. 28℃±1℃.
--Sampling volume. 20 µL.
A.5.3.3 Drawing the standard curve of retinol
Respectively take the retinol standard series solution from low to high for determination, and add retinol with the same concentration as the internal standard in the standard for each determination
The alcohol acetate internal standard was used for the determination. Take the concentration of retinol standard series solution as the abscissa, and take the peak area of retinol and the internal standard of retinol acetate
Draw a standard curve for the ratio of peak area to the ordinate, and perform linear regression (r2 ≥ 0.999). The internal standard measures two parallel samples.
A.5.4 Determination of retinol in blood samples
A.5.4.1 Frozen serum (plasma) blood samples need to be naturally thawed at room temperature and protected from light, and shaken to mix. Fresh serum (blood
The blood sample can be directly used for the next step.
A.5.4.2 Draw 100 µL each of serum (plasma) and internal standard into a 1.5 mL centrifuge tube, shake and mix for 30 s, add 1 mL of n-hexane to extract, shake
Swing for 1 min.
A.5.4.3 Centrifuge at 5000 r/min for 5 minutes, take out 800 µL of the supernatant and transfer it to another 1.5 mL centrifuge tube.
A.5.4.4 After drying with nitrogen, add.200 µL of ethanol to dissolve, shake and mix for 30 s, centrifuge for 5 min, 5000 r/min.
A.5.4.5 Aspirate 150 µL of the sample solution and use a high-performance liquid chromatography for detection. According to the peak area of retinol in the chromatogram
The ratio of the peak area of the retinol acetate internal standard is calculated on the standard curve to find the content of retinol in the sample.
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