CN102507483A - Method for determining content of calcium carbonate in cigarette paper - Google Patents

Abstract

The invention discloses a method for determining the content of calcium carbonate in cigarette paper, which comprises the steps of: treating the cigarette paper to be determined with hydrochloric acid and distilled water and filtering, adding a potassium iodate aqueous solution and a potassium iodide aqueous solution into the filtrate for reaction; diluting with distilled water without carbon dioxide and analyzing with a spectrophotometer at wavelength of 352nm; and then drawing a standard curve and calculating to obtain the result. In the invention, the spectrophotometer is applied to determining calcium carbonate in cigarette paper for the first time. The recovery rate is 98.2-100.8% and variation coefficient range of continuous five-time determining results is 0.0031-0.40%. The inter-day variation coefficient range is 1.34%. There is no significant difference when comparing the determining result by national standard method with the result by the method of the invention. The method is simple and convenient to operate, fast to analyze, and has high accuracy and precision, strong stability and good application prospect.

Description

A kind of method of measuring calcium carbonate content in the cigarette paper

Technical field

The invention belongs to cigarette material physical and chemical inspection technical field, be specifically related to a kind of method that can accurately measure calcium carbonate content in the cigarette paper.

Background technology

Lime carbonate not only influences the exterior quality of cigarette paper; Like whiteness, opacity etc., also affect gas penetration potential that cigarette props up, flammability, bag ash performance etc., play an important role for the cigarette lowering harm and decreasing coking; So, be an important indicator of cigarette paper quality control always.Because of the product after its burning does not hinder health, for many years, or even unique filler of cigarette paper.In the prior art, the report of measuring based on potentiometric titration, thermogravimetric mass spectroscopy etc. is arranged.But all there is the comparatively loaded down with trivial details problem of operation in these methods.

AAS is a kind of common analytical approach, and it absorbs to measure content of material the selectivity of light based on material, has that analysis speed is fast, accuracy and advantages such as precision is high, easy and simple to handle, highly versatile.If this method is applied to the detection of cigarette paper, should be able to overcomes the deficiency that existing detection method exists well, but the report of success is not arranged in the prior art as yet.

Summary of the invention

The objective of the invention is to the deficiency to prior art, a kind of method of measuring calcium carbonate content in the cigarette paper is provided, the utilization AAS under the prerequisite that guarantees accuracy in detection, precision and stability, is simplified the process of measuring.

The object of the invention is achieved through following technical scheme.

Except as otherwise noted, the percentage that the present invention adopted is percent by weight.

A kind of method of measuring calcium carbonate content in the cigarette paper may further comprise the steps:

1, cigarette paper to be measured is shredded and dry to constant weight; Take by weighing the 0.50g paper scrap, place the 150mL beaker, adding concentration is the aqueous hydrochloric acid solution 35.0mL of 0.1mol/L; After being stirred well to fiber dispersion, no bubble and overflowing; The distilled water of adding 65.0mL removing carbon dioxide fully mixes the back and filters with qualitative filter paper, and collection filtrating is for use;

2, get 2.0mL and filtrate in the 50mL volumetric flask, adding concentration is the Potassiumiodate aqueous solution 2.0mL of 5g/L, and concentration is the potassium iodide aqueous solution 3.0mL of 50g/L; React after 5 minutes; The distilled water diluting of using removing carbon dioxide is to scale, and mixing is analyzed in the 352nm wavelength with spectrophotometer;

3, drawing standard curve: the hydrochloric acid solution 1.0,2.0,3.0,4.0, the 5.0mL that pipette proven 0.1mol/L with transfer pipet respectively; Be settled to 100mL; After step (2) colour developing and measuring, be horizontal ordinate with the absorbance, calcium carbonate content is an ordinate drawing standard working curve; Calcium carbonate content by formula (1) calculates:

$\mathrm{CaO}(\%)=\frac{28\left[C_{\mathrm{HCl}}(V_{\mathrm{HCl}}-V_{\mathrm{Std}})\right]}{G\×1000}\×100\%$ Formula (1)

In the formula:

Calcium carbonate content in the CaO%-cigarette paper, unit are mass percent (%);

C _HClThe accurate concentration of-0.1mol/L HCl standard solution, unit is every liter (mol/L) of mole;

V _HCl-adding the volume of 0.1mol/L HCl standard solution, unit is a milliliter (mL);

V _Std-0.1mol/L HCl standard solution the volume of being taken when painting typical curve, unit are milliliter (mL);

The calcium oxide quality of the every mole hydrochloride reaction consumes of 28-, unit is every mole (g/mol) of gram;

The 1000-volume conversion factor will use the volume of the standard solution of milliliter (mL) expression to be transformed into liter (L);

The G-sample quality, unit is gram (g).

4, the result calculates: solution absorbency per sample; Read the result from typical curve, deduction obtains the calcium carbonate content of sample after the blank, serve as final mensuration result with the mean value of twice replicate determination; The difference of absolute value should be above 0.4% as a result to be accurate to 0.1%, twice replicate determination.

With respect to prior art, the present invention has the following advantages: the present invention is applied to AAS the mensuration of lime carbonate in the cigarette paper initiatively.Its recovery scope is 98.2～100.8%, and the continuous coefficient of variation scope of measuring results for 5 times is: 0.0031～0.40%, and coefficient of variation scope is in the daytime: 1.34%, compare no significant difference with the testing result of national standard method.This method is easy and simple to handle, analysis speed is fast, and accuracy and precision are high, stability is strong, have a good application prospect.

Description of drawings

Fig. 1 potassium iodate solution addition is to the influence of sample solution absorbance;

Fig. 2 liquor kalii iodide addition is to the influence of sample solution absorbance;

Fig. 3 reaction time is to the influence of sample solution absorbance;

Fig. 4 sample standing time is to the influence of sample solution absorbance;

Fig. 5 standard working curve.

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is done further detailed description, but accompanying drawing and embodiment are not the qualification to technical scheme of the present invention, all should belong to protection scope of the present invention based on the variation that training centre of the present invention is done.

Embodiment 1

1. experimental principle, material and method

1.1 experimental principle

The excessive HCl solution reaction of cigarette paper sample and known accurate amount is through detecting remaining H+ with AAS.The content of acid is directly proportional with the colour developing production concentration, can measure in the 352nm place.Can extrapolate cigarette paper calcium carbonate content (in CaO) by acid content.

1.2 material and instrument

Potassiumiodate (AR, prompt chemical reagent company limited is moistened in Shanghai); Potassium iodide (AR, Shanghai chemical reagent company limited), hydrochloric acid (AR, Shantou Xilong Chemical Factory, Guangdong); Lime carbonate (working standard reagent (capacity), analysis on trace institute of Tongji University); The distilled water of removing carbon dioxide (self-control); 4 cigarette paper samples are Yunnan Hongta Lanying Paper Industry Co., Ltd.'s product.

JA5002 balance (sensibility reciprocal 0.01g, Shanghai balance equipment factory); METLER AE200 analytical balance (sensibility reciprocal: 0.0001g, Switzerland METLER TOLEDO company); HP5873 ultraviolet-visible pectrophotometer (U.S. Hewlett-Packard Corporation); 101A-2 drying box (Shanghai City experimental apparatus head factory).

1.3 sample preparation and analysis

1.3.1 acid reaction

Take by weighing the dry to constant weight paper scrap (0.5cm * 2.5cm) of (being accurate to 0.01g) of 0.5g; Put into the 150mL beaker; Add 0.1mol/L hydrochloric acid solution 35.0mL with transfer pipet, after being stirred well to fiber dispersion, no bubble and overflowing with glass rod, with transfer pipet adding 65.0mL deionized water; Fully mix the back and filter with qualitative filter paper, collection filtrating is for use.

1.3.2 colour developing and mensuration

Get 2.0mL and filtrate in the 50mL volumetric flask, add 5g/L Potassiumiodate WS 2.0mL, 50g/L potassium iodide aqueous solution 3.0mL reacted after 5 minutes, and to scale, mixing is analyzed in the 352nm wavelength with spectrophotometer with the distilled water diluting of removing carbon dioxide.

2. result and discussion

2.1 choice of experimental conditions

2.1.1 wavelength is selected

With 1nm is at interval; Light absorption to standard specimen from 200nm to 700nm scans, and the gained absorption curve shows has two absorption peaks, is respectively 280nm and 352nm; Consider that the 280nm chaff interference is more, therefore select to have more distinctive 352nm as the optimal wavelength of analyzing.

2.1.2 the potassium iodate solution consumption is to the influence of sample solution absorbance

Keep other condition constant, add the 5g/L Potassiumiodate WS of different amounts, the absorbance log of sample solution changes like Fig. 1.The result shows that the Potassiumiodate amount of aqueous solution used is to the not obviously influence of sample solution absorbance.This experimental selection 2.0mL.

2.1.3 the liquor kalii iodide consumption is to the influence of sample solution absorbance

Other condition is constant, adds 50g/L liquor kalii iodide 0.4ml, 0.8ml, 1.2mL, 1.6mL, 2.0mL, 3.0mL, 5.0mL, 8.0mL respectively, surveys absorbance, and is as shown in Figure 2, the addition of liquor kalii iodide during greater than 3mL absorbance change less.So selecting 3.0mL is the addition of liquor kalii iodide.

2.1.4 the reaction time is to the influence of sample solution absorbance

After three kinds of reagent mix, reaction takes place immediately, and it is faint yellow that solution is, and different reaction durations produces different absorbances.Keep other condition constant, the absorbance variation of reacting respectively after 0,1,2,5,15 minute sees that Fig. 3, result show, chemical reaction is very fast, and afterreaction reached stable in 5 minutes, so 5 minutes choice reaction time.

2.1.5 sample solution test stabilization time

Sample solution was placed 2,5,10,20,30,60,180,300 minutes respectively at room temperature, measured its stability.Test findings is seen Fig. 4.It is thus clear that sample was stable in 3 hours.

2.2 typical curve

Preparation and demarcation concentration are the hydrochloric acid solution of 0.1074mol/L, pipette this solution 1.0,2.0,3.0,4.0,5.0mL respectively with transfer pipet, are settled to 100mL; After the 1.3.2 colour developing and measuring, calculate corresponding calcium carbonate content (in CaO) according to formula (1), obtain standard working curve like Fig. 5; The x axle is a solution absorbency; The y axle is calcium carbonate content (in CaO)), equation of linear regression is y=-0.6014x+21.65, coefficient R 2=1.

2.3 the recovery

In the pattern of known content (mean values of 3 mensuration), add lime carbonate a certain amount of, that behind 110～120 ℃ of baking 1.5～2h, in sulphuric acid desiccator, cool off; Measure its lime carbonate; The recovery is respectively 98.2%, 100.8% (seeing table 1); The accuracy of illustration method is good, and testing result is reliable.

Table 1 recovery

2.4 repeatability

A, B, C, a D4 sample are distinguished continuous detecting 5 times, and the result sees table 2.The coefficient of variation is 0.40% to the maximum, explains that the precision of this method is high.

The reperformance test result of table 2 AAS

2.5 stability test

The C sample is detected 3 times at different time, and each sample continuous detecting 5 times the results are shown in Table 3.The coefficient of variation is 1.34%, explains that this method has good stability.

The stability test result of table 3 AAS

Annotate: 1. each data is the mean value of continuous 5 measurement results

2.6 comparison with other method

Detect 4 samples respectively with AAS and potentiometric titration, the result sees table 4.AAS is compared with potentiometric titration, and detected value is on the low side, but difference is less, and maximum difference is 0.3%, explains that AAS is consistent with the potentiometric titration testing result.

Table 4 AAS and other method testing result are relatively

3, conclusion

Utilize that spectrophotometry cigarette paper lime carbonate is easy and simple to handle, the result is accurate, precision is high, good stability, with other consistent with methods and results, be a kind ofly can satisfy the method that modernized production of cigarettes detects.

Claims (1)

1. method of measuring calcium carbonate content in the cigarette paper may further comprise the steps:

(1) cigarette paper to be measured is shredded and dry to constant weight; Take by weighing the 0.50g paper scrap, place the 150mL beaker, adding concentration is the aqueous hydrochloric acid solution 35.0mL of 0.1mol/L; After being stirred well to fiber dispersion, no bubble and overflowing; The distilled water of adding 65.0mL removing carbon dioxide fully mixes the back and filters with qualitative filter paper, and collection filtrating is for use;

(2) get 2.0mL and filtrate in the 50mL volumetric flask, adding concentration is the Potassiumiodate aqueous solution 2.0mL of 5g/L, and concentration is the potassium iodide aqueous solution 3.0mL of 50g/L; React after 5 minutes; The distilled water diluting of using removing carbon dioxide is to scale, and mixing is analyzed in the 352nm wavelength with spectrophotometer;

(3) drawing standard curve: the hydrochloric acid solution 1.0,2.0,3.0,4.0, the 5.0mL that pipette proven 0.1mol/L with transfer pipet respectively; Be settled to 100mL; After step (2) colour developing and measuring, be horizontal ordinate with the absorbance, calcium carbonate content is an ordinate drawing standard working curve; Calcium carbonate content by formula (1) calculates:

$\mathrm{CaO}(\%)=\frac{28\left[C_{\mathrm{HCl}}(V_{\mathrm{HCl}}-V_{\mathrm{Std}})\right]}{G\×1000}\×100\%$ Formula (1)

In the formula:

Calcium carbonate content in the CaO%-cigarette paper, unit are mass percent (%);

C _HClThe accurate concentration of-0.1mol/L HCl standard solution, unit is every liter (mol/L) of mole;

V _BCl-adding the volume of 0.1mol/L HCl standard solution, unit is a milliliter (mL);

V _Std-0.1mol/L HCl standard solution the volume of being taken when painting typical curve, unit are milliliter (mL);

The calcium oxide quality of the every mole hydrochloride reaction consumes of 28-, unit is every mole (g/mol) of gram;

The 1000-volume conversion factor will use the volume of the standard solution of milliliter (mL) expression to be transformed into liter (L);

The G-sample quality, unit is gram (g);

(4) result calculates: solution absorbency per sample; Read the result from typical curve, deduction obtains the calcium carbonate content of sample after the blank, serve as final mensuration result with the mean value of twice replicate determination; The difference of absolute value should be above 0.4% as a result to be accurate to 0.1%, twice replicate determination.

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