CN101419205A - Method for measuring residual organic solvent in pectins - Google Patents

Abstract

The invention discloses a method for measuring residual organic solvents in a pectin, which makes use of an organic solvent, namely n-butanol to extract the residual organic solvents in the pectin and comprises the following steps: a. pectin sample pre-treatment; b. instrumental analysis; and c. result calculation. The method has simple operation and accurate test result, and can effectively test the residual organic solvents in the pectin.

Description

The assay method of residual organic solvent in a kind of pectin

Technical field:

The present invention relates to the pectin production technical field, is the assay method of residual organic solvent in a kind of pectin specifically, promptly utilizes the method for residual organic solvent in the gas chromatographic detection pectin.

Background technology:

In the pectin production run, a step of most critical is to do precipitation agent with ethanol or isopropyl alcohol organic solvent, and precipitation concentrates the pectin in the pectin juice, and in process of production, pectin molecule produces harmful material-methyl alcohol after taking off ester under the effect of acid.Limit the quantity of and to cause certain harm to human body if these organic solvent residuals exceed,, residues of harmful substances in the food is required also more and more strictness, therefore must be controlled along with the enhancing of health of people consciousness.But pectin is different from general organism, and it is insoluble in the water, more is insoluble in the organic solvent, and handle very complexity the early stage of the assay method of residual organic solvent in the present existing pectin, is not easy to operation.

Summary of the invention:

The objective of the invention is to overcome the deficiency of above-mentioned prior art, and the assay method of residual organic solvent in a kind of pectin be provided, handle the early stage that mainly solves the assay method of residual organic solvent in the existing pectin complicated, be not easy to problem such as operation.

In order to achieve the above object, the present invention is achieved in that the assay method of residual organic solvent in a kind of pectin, and its special character is that it comprises following processing step:

A, pectin sample pre-treatment places iodine flask with sample, adds the chromatogram normal butyl alcohol, places and stirs 30min extraction back on the magnetic stirring apparatus, adopts the vacuum filtration mode to filter, and collects filtrate, and with the final constant volume of normal butyl alcohol; Do the reagent blank test simultaneously;

B, above-mentioned constant volume liquid is got in instrumental analysis, the chromatogram sample introduction, chromatographic condition is:

1) the chromatographic column model is DB-WAXTER;

2) temperature programme condition: 50 ℃ keep 4min, rise to 190 ℃ with the heating rate of 20 ℃/min, keep 2min;

3) injector temperature: 220 ℃;

4) detector temperature: 280 ℃;

5) column flow rate: 1mL/min, hydrogen flow rate: 30mL/min, air velocity: 400mL/min, tail wind drift speed: 29mL/min;

6) sample size: 1 μ L;

7) split ratio: 25:1.

C, the result calculates

$X=\frac{(c-c_0)\×v}{m}$

In the formula, X---Determination of Residual Organic Solvents in the pectin, mg/kg;

C---organic solvent concentration in the sample constant volume liquid, mg/L;

c ₀---organic solvent concentration in the reagent blank liquid, mg/L;

V---constant volume liquid is long-pending, mL;

The quality of m---sample, g.

Compared with the prior art the assay method of residual organic solvent has outstanding substantive distinguishing features and marked improvement in a kind of pectin of the present invention, it is extractant that this assay method is selected normal butyl alcohol for use, handle simple, easy to operate early stage, testing result is accurate, can detect the organic solvent residual in the pectin effectively; Be convenient to handle residual organic solvent in the pectin better, guarantee to contain the security of pectin food.

Embodiment:

In order to understand better and to implement, describe the assay method of residual organic solvent in a kind of pectin of the present invention in detail below in conjunction with embodiment.

Embodiment 1, and selecting normal butyl alcohol for use is extractant, takes by weighing the 2.00g sample in the 100ml iodine flask, add 20ml chromatogram normal butyl alcohol, place and stir 30min extraction back on the magnetic stirring apparatus, adopt the vacuum filtration mode to filter, collect filtrate, and finally be settled to 30ml with normal butyl alcohol; Do the reagent blank test simultaneously; Get 2ml constant volume liquid, the chromatogram sample introduction, chromatographic condition is: the chromatographic column model is DB-WAXTER, the temperature programme condition: 50 ℃ keep 4min, rise to 190 ℃ with the heating rate of 20 ℃/min, keep 2min, injector temperature: 220 ℃, detector temperature: 280 ℃, column flow rate: 1mL/min, hydrogen flow rate: 30mL/min, air velocity: 400mL/min, tail wind drift speed: 29mL/min, sample size: 1 μ L, split ratio: 25:1; Calculate by following formula then: $X=\frac{(c-c_0)\×v}{m}$ In the formula, X---Determination of Residual Organic Solvents in the pectin, mg/kg, c---organic solvent concentration in the sample constant volume liquid, mg/L, c ₀---organic solvent concentration in the reagent blank liquid, mg/L, v---constant volume liquid is long-pending, mL, the quality of m---sample, g.

Claims (1)

1, the assay method of residual organic solvent in a kind of pectin is characterized in that it comprises the steps:

A, pectin sample pre-treatment places iodine flask with sample, adds the chromatogram normal butyl alcohol, places and stirs 30min extraction back on the magnetic stirring apparatus, adopts the vacuum filtration mode to filter, and collects filtrate, and with the final constant volume of normal butyl alcohol; Do the reagent blank test simultaneously;

B, above-mentioned constant volume liquid is got in instrumental analysis, the chromatogram sample introduction, chromatographic condition is:

1) the chromatographic column model is DB-WAXTER;

2) temperature programme condition: 50 ℃ keep 4min, rise to 190 ℃ with the heating rate of 20 ℃/min, keep 2min;

3) injector temperature: 220 ℃;

4) detector temperature: 280 ℃;

5) column flow rate: 1mL/min, hydrogen flow rate: 30mL/min, air velocity: 400mL/min, tail wind drift speed: 29mL/min;

6) sample size: 1 μ L;

7) split ratio: 25:1.

C, the result calculates

$X=\frac{(c-c_0)\×v}{m}$

In the formula,

X---Determination of Residual Organic Solvents in the pectin, mg/kg;

C---organic solvent concentration in the sample constant volume liquid, mg/L;

c ₀---organic solvent concentration in the reagent blank liquid, mg/L;

V---constant volume liquid is long-pending, mL;

The quality of m---sample, g.