Method for simultaneously determining contents of various preservatives in soy by capillary gas chromatography internal standard method

A technology of gas chromatography and internal standard method, which is applied in the field of detection of various preservatives in soy sauce, can solve the problems of unsatisfactory precision and accuracy, increased operational errors in the measurement steps, difficult stratification, etc., and achieves sample pretreatment time The effect of shortening, improving utilization rate, and easy operation

Inactive Publication Date: 2012-01-18
GUANGDONG MEIWEIXIAN FLAVORING & FOOD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The current testing standards are GB / T 5009.29-2003 "Determination of Sorbic Acid and Benzoic Acid in Food" and GB / T5009.31-2003 "Determination of Parabens in Food". For the determination of the content of various preservatives in soy sauce, a sample needs to be pretreated by two methods and different instrument conditions, which is time-consuming and labor-intensive.
Moreover, it has been found through practice that when directly using this standard to detect soy sauce products, the recovery rate of standard addition is low, the measurement result is unstable, and it is also easy to be caused by emulsification when extracting relatively thick old soy sauce samples. Occurs and is difficult to stratify for subsequent operations
Therefore, when the gas chromatography method in this standard is used directly to detect soy sauce products, especially the old soy samples, the precision and accuracy are not ideal. This is because the external standard method is used for quantification. It may lead to errors. The cumbersome measurement steps increase the probability of operational errors. The measurement on the machine requires a relatively high instrument performance and configuration, such as the need to configure an automatic sampler to ensure accurate control of the injection volume, etc.

Method used

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  • Method for simultaneously determining contents of various preservatives in soy by capillary gas chromatography internal standard method
  • Method for simultaneously determining contents of various preservatives in soy by capillary gas chromatography internal standard method

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] 1. Chromatographic conditions:

[0024] Gas chromatograph equipped with FID detector;

[0025] The capillary column is DB-WAX (30m×0.32mm×0.25μm)

[0026] The column temperature is 210°C, the vaporization chamber and the detection chamber are both 230°C

[0027] Manual injection 1.0μl

[0028] The carrier gas is high-purity nitrogen, the column head pressure is 0.07Mpa, and the split ratio is 100:1

[0029] 2. Correction Factor Determination

[0030] Preparation of standard solution: Accurately weigh 0.2g each of benzoic acid and sorbic acid, dissolve in acetone and dilute to 100ml;

[0031] Prepare internal standard solution: Accurately weigh 0.2 g of methyl heptadecanoate, dissolve it in acetone and set the volume to 100 ml;

[0032] Preparation of standard solution: Take an appropriate amount of standard solution and mix with internal standard solution, the concentration of internal standard is 0.4g / L, and the concentration of standard substance is 0.2, 0.4, 0.6...

Embodiment 2

[0039] 1. Chromatographic conditions:

[0040] Gas chromatograph equipped with FID detector;

[0041] The capillary column is DB-WAX (30m×0.32mm×0.25μm)

[0042] The column temperature is 210°C, the vaporization chamber and detection room temperature are 230°C

[0043] Manual injection 0.5μl

[0044] The carrier gas is high-purity nitrogen, the column head pressure is 0.07Mpa, and the split ratio is 100:1

[0045] 2. Correction Factor Determination

[0046] Preparation of standard solution: Accurately weigh 0.2g each of benzoic acid, sorbic acid, dehydroacetic acid, methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, and propyl p-hydroxybenzoate, dissolve in acetone and dilute to 100ml;

[0047] Prepare internal standard solution: Accurately weigh 0.2 g of methyl heptadecanoate, dissolve it in acetone and set the volume to 100 ml;

[0048] Preparation of standard solution: Take an appropriate amount of standard solution and mix it with internal standard solution. The conc...

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Abstract

The invention discloses a method for simultaneously determining contents of various preservatives in soy by a capillary gas chromatography internal standard method, which comprises the following steps of: (1) weighing a soy sample; (2) adding an internal standard solution in the sample, and then sequentially being subjected to acidification, ether extraction, water removal water by purification and concentration treatment to obtain a sample solution; (3) taking the sample solution from the step (2) to be subjected to gas chromatography to obtain chromatographic data; and (4) comparing the chromatographic data obtained from the step (3) with the preset standard data of preservatives to obtain the contents of various preservatives in the soy. The method can simultaneously determine the contents of preservatives such as benzoic acid, sorbic acid, dehydroacetic acid and paraben esters and the like in the soy, is simple and convenient to operate, and is easy to implement, the impact of operation error, instrument conditions and other factors on determination results can be effectively reduced, and the results are accurate and reliable.

Description

technical field [0001] The invention relates to a method for detecting the contents of various preservatives in soy sauce, in particular to a method for simultaneously measuring the contents of various preservatives in soy sauce by a capillary gas chromatography internal standard method. Background technique [0002] Soy sauce is a nutritious and delicious condiment. It may be spoiled when it is polluted by microorganisms. Therefore, the manufacturer will add some edible preservatives to inhibit possible spoilage. The commonly used preservatives in soy sauce are benzene Formic acid, sorbic acid, and parabens, etc. National standards clearly stipulate the limit of preservatives. Within the scope of safe use, preservatives have no toxic and side effects on the human body, but excessive consumption has certain toxicity to the human body. The current testing standards are GB / T 5009.29-2003 "Determination of Sorbic Acid and Benzoic Acid in Food" and GB / T5009.31-2003 "Determinati...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N30/88G01N30/06
Inventor 曾亚丽杨明泉陈穗李婕刘占张庆宇樊瑞
Owner GUANGDONG MEIWEIXIAN FLAVORING & FOOD
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