CN102706987A - Method for analyzing components in N-Phosphonomethyl aminodiacetic acid (PMIDA) mother solution - Google Patents

Abstract

The invention discloses a method for analyzing components in an N-Phosphonomethyl aminodiacetic acid (PMIDA) mother solution and relates to a component analysis method for a mother solution generated by producing the PMIDA by using iminodiacetonitrile to serve as a main raw material. The method includes the steps of independently measuring contents of the PMIDA, a nitrilotriacetic acid and an iminodiacetic acid in the mother solution, measuring polybasic acids of the PMIDA, a phosphoric acid and a phosphorous acid and the like in a substep mode, simultaneously strengthening a weak acid by adding calcium chloride, quantificationally releasing inactive hydrogen, then measuring the phosphoric acid, the nitrilotriacetic acid and the PMIDA, and skillfully measuring the contents of the iminodiacetic acid, the PMIDA, the nitrilotriacetic acid, the phosphorous acid, a hydrochloric acid and the phosphoric acid according to reaction laws and interrelations of various substances. By means of verification, the method is accurate, comprehensive, scientific and reasonable, the operation is simple, reliable evidences are provided for recycle and comprehensive usage of the PMIDA mother solution, and the method has a good popularizing value.

Description

A kind of analytical approach of PMIDA mother liquor composition

The present invention be number of patent application 201010552827.5, November 22 in 2010 applying date day, be called the dividing an application of application for a patent for invention of " a kind of analytical approach of PMIDA mother liquor composition ".

Technical field

The present invention relates to the analytical approach of PMIDA mother liquor composition, be specifically related to a kind of component analyzing method of the mother liquor that produces when being the main material production PMIDA, belong to chemical analysis field with the iminodiacetonitrile.

Background technology

PMIDA (N-(phosphoric acid methyl) iminodiacetic acid)

is to be the intermedium that raw material (IDA method) is produced glyphosate (N-(phosphonomethyl) glycine) with the iminodiacetonitrile.Glyphosate is a kind of widely used organic phosphine herbicide, and it has efficiently, the characteristics of wide spectrum, low toxicity, safety, and is very effective to the control of perennial dark root malignant weed.In recent years, because the large-scale promotion of the transgenic crop of resistance glyphosate makes that its use is convenient, the market demand of glyphosate shoots up, and constantly substitutes the herbicide of other types, occupies the first place that world's agricultural chemicals is sold for years.

Present global glyphosate production is to be main with state-of-the-art IDA method technology, accounts for more than 75%.Produce with iminodiacetonitrile in the mother liquor of PMIDA, mainly have unreacted intact raw material formaldehyde, iminodiacetic acid, phosphorous acid and hydrochloric acid, the phosphoric acid that generates after the phosphorous acid oxidation, product PMIDA and accessory substance nitrilotriacetic acid; Grasp the wherein content of each composition, all significant to the overall treatment of the recovery of material in the mother liquor, comprehensive utilization again and discarded object.Upward PMIDA mother liquor intractability is bigger but produce at present, and main cause is that its mother liquor composition is complicated, do not see the relevant report of PMIDA mother liquor analysis-by-synthesis as yet, and a lot of compositions of actual analysis PMIDA mother liquor is not set up analytical approach as yet at present.To the iminodiacetic acid Determination on content of single component in the solution, mainly adopting with the methyl red is the acid base titration of indicator at present; To the mensuration of phosphorous acid, phosphoric acid and the content of hydrochloric acid of single component in the solution, mainly adopt conventional acid base titration, directly use the alkali standard solution titration; To the PMIDA Determination on content of single component in the solution, mainly adopt the plumbi nitras standard solution to carry out complexometry, be that 9.0 damping fluid, arsenazo are as indicator with pH; Mensuration to content of formaldehyde in the solution mainly adopts sodium sulphite addition process etc.; To the mensuration of the nitrilotriacetic acid of single component, measure nitrilotriacetic acid content with nitriding in the prior art, but nitrogen-containing compound is more in the mother liquor; Disturb big, also useful soda acid compleximetry, be about to nitrilotriacetic acid with alkali dissolution after; With the firm flavescence of acid-alkali accommodation to methyl red, form complex compound behind the adding zinc nitrate solution and separate out acid, use the alkali standard solution titration; Also having with chrome azurol S-cetyl trimethyl ammonium bromide is indicator, when pH=6, uses the copper nitrate standard solution titration, but the PMIDA complicated component; Nitrilotriacetic acid and PMIDA contained in the mother liquor all have complexing, with complexometry interference are arranged, and nitrilotriacetic acid also has acidity simultaneously; It is a kind of polyprotonic acid; The same with other acidic materials in the mother liquor, can with alkali reaction, therefore can receive the interference of other materials in the mother liquor to make that the mensuration result is inaccurate when measuring nitrilotriacetic acid content with above-mentioned chemical analysis." assay of hydrochloric acid, phosphorous acid in the solution is reclaimed in PMIDA production " of Mo Qingkui; Be used for the PMIDA synthetic reaction and steam liquid hydrochloric acid, phosphorous acid assay, this steams, and the liquid composition is simple, mainly hydrochloric, phosphorous acid and formaldehyde; And mother liquor composition is complicated; Several kinds of constitutive properties respectively have similarity, and it is big to analyze difficulty, also do not have the pertinent literature report at present.

The present invention is intended to solve this difficult problem, sets up the scientific and reasonable mother liquor of PMIDA accurately analytical approach, for PMIDA mother liquor environmental protection treatment and comprehensive utilization provide the basis.

Summary of the invention

The object of the present invention is to provide a kind of is the analytical approach of component content in the PMIDA mother liquor of raw material production with the iminodiacetonitrile, and this analysis methodological science is reasonable, easy, analysis result is accurately comprehensive, has excellent popularization and is worth.PMIDA mother liquor of the present invention is meant with the iminodiacetonitrile to be the primary raw material reaction, the saturated solution of the PMIDA of generation remnants after separating.

The objective of the invention is to realize like this:

A kind of analytical approach of PMIDA mother liquor composition; Be that the content of formaldehyde, iminodiacetic acid, PMIDA and the nitrilotriacetic acid, phosphorous acid, hydrochloric acid and the phosphoric acid that contain in the PMIDA mother liquor is measured; It is characterized in that: the nitrilotriacetic acid Determination on content is with mother liquor dilution to be measured in the said mother liquor; Nitrilotriacetic acid peak area or peak height and sample size are linear up to being diluted to, and measure with high performance liquid chromatograph; With nitrilotriacetic acid is control samples, and with its dissolving, dilution, nitrilotriacetic acid peak area or peak height and sample size are linear up to being diluted to, and measure with high performance liquid chromatograph; Through (in the extension rate of the quality of control samples nitrilotriacetic acid * mother liquor to be measured * mother liquor to be measured in the peak area of nitrilotriacetic acid or the peak height * control samples quality percentage composition of nitrilotriacetic acid)/(peak area of nitrilotriacetic acid or peak height in the extension rate * control samples of the volume * control samples of mother liquor to be measured), calculate the content of nitrilotriacetic acid in the mother liquor to be measured.

Specifically, the nitrilotriacetic acid Determination on content is accurately to draw PMIDA mother liquor 5mL to be measured earlier in container in the above-mentioned mother liquor, adds moving phase and is diluted to 50mL; Shake up, drawing wherein, 10mL adds moving phase and is diluted to 25mL in container; Shake up; Behind the filtering with microporous membrane, sample introduction is measured and record aminotriacetic acid peak area with high performance liquid chromatograph; Be control samples with the nitrilotriacetic acid again, get about control samples 0.1g, in the 50mL volumetric flask; Ultrasonic concussion dissolving adds water to scale, shakes up; Draw accurately wherein that the said solution of 1.0mL adds moving phase and is diluted to scale in the 100mL volumetric flask, shake up; Behind the filtering with microporous membrane, sample introduction is measured and record aminotriacetic acid peak area with high performance liquid chromatograph; In PMIDA mother liquor to be measured

Calculate the content of nitrilotriacetic acid in the PMIDA mother liquor to be measured, m _rBe control samples quality g, C _rQuality percentage composition % for nitrilotriacetic acid in the control samples; A _rPeak area for nitrilotriacetic acid in the control samples; A _SPeak area for nitrilotriacetic acid in the PMIDA mother liquor to be measured; V is the volume mL of PMIDA mother liquor to be measured.Certainly, control samples quality m in this scheme _rCan get arbitrarily as required, be dissolved in the ratio in the 50ml moving phase as long as meet the 0.1g control samples; The volume V of PMIDA mother liquor to be measured also can get arbitrarily as required, is dissolved in the ratio in the 50ml moving phase as long as meet 5ml PMIDA mother liquor.

In order to measure the content of nitrilotriacetic acid in the mother liquor to be measured more accurately, above-mentioned dilution mother liquor to be measured and nitrilotriacetic acid control samples are with the moving phase dilution, and said moving phase is the phosphate aqueous solution of pH=2-5, or the PBS of pH=2.0; The flow velocity of said moving phase is 0.6～1.5 ml/min.

The chromatographic column that above-mentioned high performance liquid chromatograph adopts is for being the liquid spectrum post of moving phase with 100% water, like ZORBAXSB-Aq, DIKMA ODS-3 and Inertsil ODS-4 etc.

In order more accurately above-mentioned mother liquor composition content to be measured so that recycle effectively, above-mentioned to PMIDA Determination on content in the mother liquor, be that the PMIDA mother liquor is filtered; Discard filtrating just, draw subsequent filtrate 10mL in the 100mL volumetric flask, add water to scale; Shake up, draw this solution 3mL in the 250mL triangular flask, add water 100mL; Add triethanolamine solution 5mL, shake up, add 3 of borate buffer solution 20mL, arsenazo indicator solutions; Just become blueness with plumbi nitras standard titration solution titration to solution colour by aubergine, the consumption of the plumbi nitras standard titration solution that record consumes; Then according in the mother liquor

Calculate the content of PMIDA in the PMIDA mother liquor, in the formula,

Be the actual concentrations mol/L of 0.05mol/L plumbi nitras standard titration solution, V ₁Be the consumption mL of plumbi nitras standard titration solution, V ₀Be the PMIDA mother liquor volume mL that draws; The volume ratio of triethanolamine and water is 1:3 in the triethanolamine solution; Said borate buffer solution is to get boric acid 20g; Add water, add mass concentration and be 10% ammoniacal liquor 150mL, using mass concentration again is that 10% ammoniacal liquor is regulated and made pH=9.0; Add water to the solution of 1000mL, said arsenazo indicator solution is that mass concentration is 0.1% the WS.

In order to measure above-mentioned PMIDA mother liquor composition content more accurately, all sidedly, above-mentioned to iminodiacetic acid Determination on content in the PMIDA mother liquor, be to get iminodiacetic acid 0.12g earlier, place the 100mL volumetric flask, be dissolved in water and be diluted to scale; Shake up,, draw contrast solution 2mL in the 50mL volumetric flask, add hydrochloric acid solution 2mL successively, potassium bromide solution 2mL as contrast solution; Sodium nitrite solution 2mL covers tight bottle stopper, shakes up, and places 10min, transfers to bottle stopper; Water flushing bottle stopper and bottle wall add 2mL oxammonium hydrochloride solution, and vibration 1-2min treats that bubble disperses, and adds water to scale; Shake up, use the 1cm quartz colorimetric utensil to be reference with blank test, measure absorbance A r in the 350nm wavelength, said blank test be water 2mL in the 50mL volumetric flask, add hydrochloric acid solution 2mL successively; Potassium bromide solution 2mL, sodium nitrite solution 2mL covers tight bottle stopper, shakes up; Place 10min, transfer to bottle stopper, water flushing bottle stopper and bottle wall add 2mL oxammonium hydrochloride solution; Vibration 1-2min treats that bubble disperses, and adds water to scale, shakes up; Carry out PMIDA mother liquor to be measured again and measure, the PMIDA mother liquor is filtered, discard filtrating just; The accurate subsequent filtrate 2mL that draws adds water to scale in the 100mL volumetric flask, shake up; Accurate this solution 2mL that draws by the described operation of last method, is a reference with above-mentioned blank test in the 50mL volumetric flask; Measure absorbance A s, adjustment extension rate to absorbance is greater than 0.011; Then according in the mother liquor

Calculate the content of iminodiacetic acid in the PMIDA mother liquor, wherein As is a PMIDA mother liquor absorbance to be measured, and Ar is the contrast solution absorbance, m _rBe the quality g of iminodiacetic acid in the contrast solution, C% is the quality percentage composition of iminodiacetic acid in the contrast solution, and Vs is for drawing the volume mL of PMIDA mother liquor to be measured, and Bs is the extension rate of PMIDA mother liquor to be measured, and Br is the extension rate of contrast solution; Said potassium bromide solution concentration is 250g/L, and the mass ratio of hydrochloric acid and water is 1:3 in the hydrochloric acid solution, and sodium nitrite solution concentration is 70g/L, and the oxammonium hydrochloride solution concentration is 210g/L.

The mensuration of above-mentioned content of formaldehyde is that said mother liquor is filtered, discards filtrating just, draws subsequent filtrate 5mL in container, adds water 50mL; Use magnetic stirrer; With the sodium hydroxide solution neutralization, and use sodium hydrate regulator solution pH=9.20, add sodium sulfite solution 10mL; With the titration of sulfuric acid standard titration solution to pH=9.20, in mother liquor

Calculate content of formaldehyde in the mother liquor, in the formula,

Be the actual concentrations mol/L of 0.1mol/L sulfuric acid standard titration solution, V is the consumption mL of 0.1mol/L sulfuric acid standard titration solution, V _oThe cumulative volume mL that representes mother liquor to be measured; Said sodium sulfite solution concentration is 126g/L, and the concentration of sodium hydroxide solution that said neutralization is used is 200g/L, and regulating the used concentration of sodium hydroxide solution of pH=9.20 is 0.1mol/L.

The applicant infers that through the structure of matter a large amount of tests find, contains four reactive hydrogen atoms in the PMIDA molecule, and during with the standard solution of sodium hydroxide titration of 0.1mol/L, at first neutralization is Na ₂(C ₅H ₈NO ₇P), mutation range PH4.0-5.0 first stoichiometric point pH=4.5 appears; Na then ₂(C ₅H ₈NO ₇P) continue to be neutralized to Na ₃(C ₅H ₇NO ₇P), mutation range pH7.8-9.6 second stoichiometric point pH=8.7 appears; Na ₃(C ₅H ₇NO ₇P) can not direct titration, add neutral calcium chloride solution, calcium ion and PMIDA reacting generating complex quantitatively discharge acid, again with the accurate titration of standard solution of sodium hydroxide.Though nitrilotriacetic acid has three reactive hydrogen atoms, during with the standard solution of sodium hydroxide titration of 0.1mol/L, neutralization earlier is Na ₂(C ₆H ₇O ₆N), stoichiometric point pH6.5, mutation range pH4.4---8.5; During the methyl orange flavescence, 98% nitrilotriacetic acid is arranged by titration, Na ₂(C ₆H ₇O ₆N) can not direct titration, add neutral lime chloride and can produce acid, use the standard solution of sodium hydroxide titration again.Therefore; When adopting NaOH standard titration solution titration mother liquor; Selection is an indicator with methyl orange and phenolphthalein; When indicator was yellow by red stain, the hydrogen in the hydrochloric acid was neutralized by a hydrogen atom in neutralization fully, phosphorous acid, phosphoric acid, the iminodiacetic acid (salt) acid molecule, and two hydrogen atoms in PMIDA, the nitrilotriacetic acid molecule are neutralized; When phenolphthalein reddened, second hydrogen atom of phosphorous acid, phosphoric acid molecules was neutralized, the 3rd hydrogen atom in the PMIDA is neutralized; Add neutral calcium chloride solution this moment, in the PMIDA molecule in the 4th hydrogen, the nitrilotriacetic acid molecule in the 3rd hydrogen and the phosphoric acid molecules the 3rd hydrogen quantitatively discharge, use the standard solution of sodium hydroxide titration.

In order further to measure above-mentioned PMIDA mother liquor composition content accurately, all sidedly, hydrochloric acid, phosphorous acid and phosphorus acid content in the above-mentioned PMIDA mother liquor are measured, be that PMIDA mother liquor to be measured is filtered; The accurate filtrating 10mL that draws is in the 100mL volumetric flask; Add water to scale, shake up, accurate this solution 10mL that draws is in the 250mL triangular flask; Add water 40mL; 1 of methylate orange indicator solution, yellow with NaOH standard titration solution titration to the solution becomes of 0.5mol/L, the volume V of the NaOH standard titration solution that record consumes ₁, add 3 of instructions phenolphthalein solutions again, with the NaOH standard titration solution continuation titration of 0.5mol/L, to solution becomes pink, the cumulative volume V of the NaOH standard titration solution that record consumes ₂, add neutral calcium chloride solution 10mL again, shake up, drip to pink with 0.1mol/L NaOH standard titration solution, write down the volume V of the NaOH standard titration solution that consumes this moment ₃Then according in the mother liquor

In the mother liquor

In the mother liquor

Calculate the content of phosphorus acid content, phosphorus acid content and hydrochloric acid in the PMIDA mother liquor respectively, wherein C ₁Be the actual concentrations mol/L of 0.1mol/L NaOH standard titration solution, C is the actual concentrations mol/L of 0.5mol/L NaOH standard titration solution, V ₀For drawing the volume mL of PMIDA mother liquor to be measured; Said methyl orange indicator solution mass concentration 0.1%, said instructions phenolphthalein solution mass concentration is 0.1%, said neutral calcium chloride solution concentration is 200g/L.

Beneficial effect of the present invention is following:

1, the present invention is that the analytical approach of raw material production PMIDA mother liquor composition is comprehensive, scientifical rationally with the iminodiacetonitrile; Analysis result is accurate; Simple to operate, to the recovery and the comprehensive utilization of this PMIDA mother liquor reliable foundation is provided, have excellent popularization and be worth.

2, in the mensuration of analytical approach of the present invention to component content wherein, instrumental analysis is combined with chemical analysis effectively, avoided that polycomponent makes and measures the result accurately and reliably the interference of target-finding material in the mother liquor.

3, analytical approach PARA FORMALDEHYDE PRILLS(91,95) Determination on content of the present invention adopts the sodium sulphite addition process, and it does not receive the interference of other material in the mother liquor;

When 4, measuring the iminodiacetic acid (salt) acid content; Be prone to replaced the generation nitrosation reaction according to the hydrogen atom on the amino of the iminodiacetic acid (salt) acid molecule Central Asia by the nitroso-in the nitrous acid; The nitroso compound that generates has absorption maximum in the 350nm wavelength; With its content of spectrophotometry, adopt this assay method, it does not receive other material such as the interference of nitrilotriacetic acid, PMIDA etc. in the PMIDA mother liquor;

5, adopt PMIDA Determination on content method of the present invention, when measuring PMIDA content, nitrilotriacetic acid has been deducted the nitrilotriacetic acid part simultaneously by titration during calculating, make measurement result accurate;

6, analytical approach of the present invention adopts high performance liquid chromatography with after its and other separating substances to the nitrilotriacetic acid Determination on content, and with its content of external standard method, it does not receive interference, the mensuration of other materials in the mother liquor, and the result is accurate, simple to operate;

7, the present invention adopts and to add the chlorination calcium solution weak acid is strengthened; Quantitative measurement the 3rd active hydrogen and the nitrilotriacetic acid in the 4th active hydrogen of PMIDA, the phosphoric acid in the 3rd active hydrogen, to the accurate mensuration of each content of material wherein condition is provided during dexterously for the multiple acid coexistence of PMIDA, nitrilotriacetic acid, iminodiacetic acid, hydrochloric acid, phosphoric acid and phosphorous acid in the mother liquor.Recovery and comprehensive utilization to this PMIDA mother liquor provide reliable foundation.

Embodiment

Through embodiment the present invention is carried out concrete description below; Be necessary to be pointed out that at this following examples only are used for the present invention is further specified; Can not be interpreted as the restriction to protection domain of the present invention, the technician in this field can make some nonessential improvement and adjustment to the present invention according to the invention described above content.

Embodiment 1

A kind of analytical approach of PMIDA mother liquor composition, wherein nitrilotriacetic acid is measured as follows:

Instrument: Tianjin, island high performance liquid chromatograph (band UV-detector)

Chromatographic column: DIKMA ODS-3,250 * 4.5mm, 5 μ m

Moving phase: 0.1%KH ₂PO ₄, use H ₃PO ₃Regulate pH=2.0

Flow velocity: 0.8mL/min

UV：195nm

Sample size: 20 μ L

Standard solution is measured:

(AR, the nitrilotriacetic acid appearance purity of this purchase is 98%) is reference substance with nitrilotriacetic acid, takes by weighing 0.1155g in the 50mL volumetric flask; Add water and make dissolving and be diluted to scale, shake up, accurately draw this solution of 1mL in the 100mL volumetric flask; Add moving phase and be diluted to scale; Shake up, behind the filtering with microporous membrane, sample introduction.The nitrilotriacetic acid peak area is 67886.

Sample determination:

Accurately draw mother liquor 5mL in the 50mL volumetric flask, add moving phase and be diluted to scale, shake up, the accurate 10mL that draws adds moving phase and is diluted to scale in the 25mL volumetric flask, shakes up, and sample introduction behind the filtering with microporous membrane, nitrilotriacetic acid peak area are 88426.

Nitrilotriacetic acid content X in the mother liquor ₂, numerical value is represented with g/L, is calculated as follows:

$X_2=\frac{\frac{m_r}{50}\×\frac{1}{100}\×\mathrm{Cr}(\%)\×\mathrm{As}}{\frac{V}{50}\×\frac{10}{25}\×\mathrm{Ar}}\×1000=\frac{\frac{0.1155}{50}\×\frac{1}{100}\×0.98\×88426}{\frac{5}{50}\×\frac{10}{25}\×67886}\×1000=0.74(g/L)$ The PMIDA Determination on content is following in the mother liquor:

In the 100mL volumetric flask, add water to scale with pipette, extract mother liquor 10mL, shake up; As the experimental solutions of measuring PMIDA content, accurate this solution 3mL that draws adds water 100mL in the 250mL triangular flask; Triethanolamine solution (1+3) 5mL; Borate buffer solution (pH=9.0) 20mL, 3 of arsenazo (III) indicator solutions are with actual concentrations CPb (NO ₃) ₂Pb (the NO of=0.05005mol/L ₃) ₂Standard titration solution titration to solution colour has just become blueness by aubergine, consumes Pb (NO this moment ₃) ₂The volume of standard solution is 1.84mL.

PMIDA content X in the mother liquor ₃, numerical value is represented with g/L, is calculated as follows:

$X_3=\frac{\mathrm{CV}\×227.1}{\frac{V_0}{100}\×V_1}\_X_2\×1.1882=\frac{0.05005\×1.84\×227.1}{\frac{10}{100}\×3}-0.74\×1.1882=68.84(g/L)$

The iminodiacetic acid Determination on content is following in the mother liquor:

Reference substance solution is measured: get iminodiacetic acid standard model 0.1220g, place the 100mL volumetric flask, add water and make it dissolving, be diluted to scale, shake up, as contrast solution.With pipette, extract contrast solution 2mL, place the 50mL volumetric flask, add HCl solution (1+3) 2mL successively, KBr solution (250g/L) 2mL, NaNO ₂Solution (70g/L) 2mL covers tight bottle stopper, shakes up, and places 10min; Extract bottle stopper, water flushing bottle stopper and bottle wall add 2mL oxammonium hydrochloride solution (210g/L); Vibration 1-2min treats that bubble disperses, and adds water to scale; Shake up, use the 1cm quartz colorimetric utensil to sentence blank solution in 350nm and be reference, recording absorbance A r is 0.042.

Blank solution: place the 50mL volumetric flask with pipette, extract 2mL water, by above-mentioned reference substance solution assay method operation.

Sample solution is measured: mother liquor is filtered, discard filtrating just, with pipette, extract subsequent filtrate 2mL; Place the 100mL volumetric flask, add water to scale, shake up; Use experimental solutions as the iminodiacetic acid assay, accurate this solution 5mL that draws is in the 50mL volumetric flask, by last method operation; With the blank is reference (sample solution and reference substance solution are operated simultaneously), and recording absorbance A s is 0.017.

Iminodiacetic acid content X4 in the mother liquor, numerical value is represented with g/L, is calculated as follows:

$X_4=\frac{\mathrm{As}\×\frac{m_r}{100}\×2\×c\%\×1000}{\mathrm{Ar}\×\frac{\mathrm{Vs}}{100}\×5}=\frac{0.017\×\frac{0.1220}{100}\×2\×0.98}{0.042\×\frac{2}{100}\×5}\×1000=9.68(g/L)$

The mensuration of content of formaldehyde is following in the mother liquor:

With pipette, extract mother liquor 5mL, place the 150mL beaker, add water 50mL, place on the magnetic stirring apparatus, insert electrode, open and stir, the NaOH solution with 200g/L is neutralized to neutrality earlier, regulates pH=9.20 with the NaOH solution of 0.1mol/L again, adds Na ₂SO ₃(126g/L uses H to solution ₂SO ₄Standard solution is neutralized to pH=9.20) 10mL, with actual concentrations C (1/2H ₂SO ₄The H of)=0.1003mol/L ₂SO ₄Standard solution titration consumes H to pH=9.20 ₂SO ₄Standard solution is 2.99mL.

Content of formaldehyde is X in the mother liquor ₁, numerical value is represented with g/L, is calculated as follows:

$X_1=\frac{\mathrm{CV}\×30.03}{5}=\frac{0.1003\×2.99\×30.03}{5}=1.80(g/L)$

The mensuration of phosphoric acid, phosphorous acid and content of hydrochloric acid is following in the mother liquor:

With pipette, extract mother liquor 10mL, place the 100mL volumetric flask, add water to scale, shake up, use experimental solutions as hydrochloric acid, phosphoric acid and phosphorous acid assay.With this solution of pipette, extract 5mL, place the 250mL triangular flask, add water 40mL, 1 of methylate orange indicator solution is used actual concentrations C _NaOHYellow for NaOH standard titration solution titration to the solution becomes of 0.5010mol/L, consume NaOH standard titration solution volume V ₁Be 3.68mL; Add 3 of instructions phenolphthalein solutions again, continue titration to solution with the NaOH standard solution and become pink, consume NaOH standard solution cumulative volume V this moment ₂Be 4.89mL; Add neutral CaCl again ₂Solution (200g/L) 10mL shakes up, and uses actual concentrations C _NaOHNaOH standard solution titration to the solution of=0.1010mol/L becomes pink, consumes NaOH standard solution V ₃Be 3.21mL.

Phosphorus acid content X in the mother liquor ₅, phosphorous acid content X ₆, content of hydrochloric acid X ₇, numerical value is represented with g/L, is calculated as follows respectively:

$X_5=\frac{C_2{V}_3\×98.0}{\frac{V_0}{100}\×V}-X_2\×\frac{98.0}{191.1}-X_3\×\frac{98.0}{227.1}=$

$\frac{0.1010\×3.21\×98.0}{\frac{10}{100}\×5}-0.74\×\frac{98.0}{191.1}-68.84\×\frac{98.0}{227.1}=33.46(g/L)$

$X_6=\frac{C_1(V_2-V_1)\×82.00}{\frac{V_0}{100}\×V}-X_3\×\frac{82.00}{227.1}-X_5\×\frac{82.0}{98.0}=$

$\frac{0.5010\×(4.89-3.68)\×82.00}{\frac{10}{100}\×55}-68.84\×\frac{82.00}{227.1}-33.46\×\frac{82.00}{98.0}=46.56(g/L)$

$X_7=\frac{C_1{V}_1\×36.5}{\frac{v_0}{100}\×V}-X_2\×\frac{72.9}{191.14}-X_3\×\frac{72.9}{227.1}-X_4\×\frac{36.5}{133.1}-X_5\×\frac{36.5}{97.99}-X_6\×\frac{36.5}{82.00}$

$=\frac{0.5010\×3.68\×36.5}{\frac{10}{100}\×5}-0.74\×\frac{72.9}{191.1}-68.84\×\frac{72.9}{227.1}-9.68\×\frac{36.5}{133.1}-33.46\×\frac{36.5}{98.0}-$

$46.56\×\frac{36.5}{82.00}=76.26(g/L)$

Embodiment 2

A kind of analytical approach of PMIDA mother liquor composition, wherein nitrilotriacetic acid is measured as follows:

Instrument: Tianjin, island high performance liquid chromatograph (band UV-detector)

Chromatographic column: InertsilODS-4,250 * 4.5mm, 5 μ m

Moving phase: 0.15%H ₃PO ₄The WS, pH=3.0

Flow velocity: 0.6mL/min

UV：195nm

Sample size: 20 μ L

Standard solution is measured:

(AR, the nitrilotriacetic acid appearance purity of this purchase is 98%) is reference substance with nitrilotriacetic acid, takes by weighing 0.1000g in the 50mL volumetric flask; Add water and make dissolving and be diluted to scale, shake up, accurately draw this solution of 1mL in the 100mL volumetric flask; Add moving phase and be diluted to scale; Shake up, behind the filtering with microporous membrane, sample introduction.The nitrilotriacetic acid peak area is 66428.

Sample determination:

Accurately draw mother liquor 5mL in the 50mL volumetric flask, add moving phase and be diluted to scale, shake up, the accurate 10mL that draws adds moving phase and is diluted to scale in the 25mL volumetric flask, shakes up, and sample introduction behind the filtering with microporous membrane, nitrilotriacetic acid peak area are 80793.

Nitrilotriacetic acid content X in the mother liquor ₂, numerical value is represented with g/L, is calculated as follows:

$X_2=\frac{\frac{m_r}{50}\×\frac{1}{100}\×\mathrm{Cr}(\%)\×\mathrm{As}}{\frac{V}{50}\×\frac{10}{25}\×\mathrm{Ar}}\×1000=\frac{\frac{0.1000}{50}\×\frac{1}{100}\×0.98\×80793}{\frac{5}{50}\×\frac{10}{25}\×66428}\×1000=0.60(g/L)$

The employing of the content of iminodiacetic acid is the determination of acid-basetitration of indicator with the methyl red in this mother liquor; Phosphorous acid, phosphoric acid and content of hydrochloric acid adopt conventional determination of acid-basetitration; PMIDA content in the mother liquor, adopt with pH be 9.0 damping fluid, arsenazo as indicator, the plumbi nitras standard solution carries out complexometry; To acid base titration after the mensuration employing sodium sulphite addition of content of formaldehyde in the solution.

Embodiment 3

A kind of analytical approach of PMIDA mother liquor composition, wherein nitrilotriacetic acid is measured as follows:

Instrument: Tianjin, island high performance liquid chromatograph (band UV-detector)

Chromatographic column: DIKMA ODS-3,250 * 4.5mm, 5 μ m

Moving phase: 0.2%KH ₂PO ₄, use H ₃PO ₄Regulate pH=2.0

Flow velocity: 1.5mL/min

UV：195nm

Sample size: 20 μ L

Standard solution is measured:

(AR, the nitrilotriacetic acid appearance purity of this purchase is 98%) is reference substance with nitrilotriacetic acid, takes by weighing 0.1155g in the 50mL volumetric flask; Add water and make dissolving and be diluted to scale, shake up, accurately draw this solution of 1mL in the 100mL volumetric flask; Add moving phase and be diluted to scale; Shake up, behind the filtering with microporous membrane, sample introduction.The nitrilotriacetic acid peak area is 66101.

Sample determination:

Accurately draw mother liquor 5mL in the 50mL volumetric flask, add moving phase and be diluted to scale, shake up, the accurate 10mL that draws adds moving phase and is diluted to scale in the 25mL volumetric flask, shakes up, and sample introduction behind the filtering with microporous membrane, nitrilotriacetic acid peak area are 88617.

Nitrilotriacetic acid content X in the mother liquor ₂, numerical value is represented with g/L, is calculated as follows:

$X_2=\frac{\frac{m_r}{50}\×\frac{1}{100}\×\mathrm{Cr}(\%)\×\mathrm{As}}{\frac{V}{50}\×\frac{10}{25}\×\mathrm{Ar}}\×1000=\frac{\frac{0.1155}{50}\×\frac{1}{100}\×0.98\×88617}{\frac{5}{50}\×\frac{10}{25}\×66101}\×1000=0.76(g/L)$ PMIDA content is measured by following in the mother liquor:

In the 100mL volumetric flask, add water to scale with pipette, extract mother liquor 10mL, shake up; As the experimental solutions of measuring PMIDA content, accurate this solution 3mL that draws adds water 100mL in the 250mL triangular flask; Triethanolamine solution (1+3) 5mL; Borate buffer solution (pH=9.0) 20mL, 3 of arsenazo (III) indicator solutions are with actual concentrations CPb (NO ₃) ₂Pb (the NO of=0.05005mol/L ₃) ₂Standard titration solution titration to solution colour has just become blueness by aubergine, consumes Pb (NO this moment ₃) ₂The volume of standard solution is 1.69mL.

PMIDA content X in the mother liquor ₃, numerical value is represented with g/L, is calculated as follows:

$X_3=\frac{\mathrm{CV}\×227.1}{\frac{V_0}{100}\×V_1}\_X_2\×1.1882=\frac{0.05005\×1.69\×227.1}{\frac{10}{100}\×3}-0.76\×1.1882=63.13(g/L)$

The employing of the content of iminodiacetic acid is the determination of acid-basetitration of indicator with the methyl red in this mother liquor; Phosphorous acid, phosphoric acid and content of hydrochloric acid adopt conventional determination of acid-basetitration; To acid base titration after the mensuration employing sodium sulphite addition of content of formaldehyde in the solution.

Embodiment 4

A kind of analytical approach of PMIDA mother liquor composition, wherein nitrilotriacetic acid is measured as follows:

Instrument: Tianjin, island high performance liquid chromatograph (band UV-detector)

Chromatographic column: ZORBAXSB-Aq, 250 * 4.5mm, 5 μ m

Moving phase: 0.25%KH ₂PO ₄, use H ₃PO ₄Regulate pH=2.0

Flow velocity: 1.0mL/min

UV：195nm

Sample size: 20 μ L

Standard solution is measured:

(AR, the nitrilotriacetic acid appearance purity of this purchase is 98%) is reference substance with nitrilotriacetic acid, takes by weighing 0.1155g in the 50mL volumetric flask; Add water and make dissolving and be diluted to scale, shake up, accurately draw this solution of 1mL in the 100mL volumetric flask; Add moving phase and be diluted to scale; Shake up, behind the filtering with microporous membrane, sample introduction.The nitrilotriacetic acid peak area is 67712.

Sample determination:

Accurately draw mother liquor 5mL in the 50mL volumetric flask, add moving phase and be diluted to scale, shake up, the accurate 10mL that draws adds moving phase and is diluted to scale in the 25mL volumetric flask, shakes up, and sample introduction behind the filtering with microporous membrane, nitrilotriacetic acid peak area are 79024.

Nitrilotriacetic acid content X in the mother liquor ₂, numerical value is represented with g/L, is calculated as follows:

$X_2=\frac{\frac{m_r}{50}\×\frac{1}{100}\×\mathrm{Cr}(\%)\×\mathrm{As}}{\frac{V}{50}\×\frac{10}{25}\×\mathrm{Ar}}\×1000=\frac{\frac{0.1155}{50}\×\frac{1}{100}\×0.98\×79024}{\frac{5}{50}\×\frac{10}{25}\×67712}\×1000=0.66(g/L)$ The PMIDA Determination on content is following in the mother liquor:

In the 100mL volumetric flask, add water to scale with pipette, extract mother liquor 10mL, shake up; As the experimental solutions of measuring PMIDA content, accurate this solution 3mL that draws adds water 100mL in the 250mL triangular flask; Triethanolamine solution (1+3) 5mL; Borate buffer solution (pH=9.0) 20mL, 3 of arsenazo (III) indicator solutions are with actual concentrations CPb (NO ₃) ₂Pb (the NO of=0.05005mol/L ₃) ₂Standard titration solution titration to solution colour has just become blueness by aubergine, consumes Pb (NO this moment ₃) ₂The volume of standard solution is 1.40mL.

PMIDA content X in the mother liquor ₃, numerical value is represented with g/L, is calculated as follows:

$X_3=\frac{\mathrm{CV}\×227.1}{\frac{V_0}{100}\×V_1}\_X_2\×1.1882=\frac{0.05005\×1.40\×227.1}{\frac{10}{100}\×3}-0.66\×1.1882=52.26(g/L)$

The iminodiacetic acid Determination on content is following in the mother liquor:

Reference substance solution is measured: get iminodiacetic acid standard model 0.1220g, place the 100mL volumetric flask, add water and make it dissolving, be diluted to scale, shake up, as contrast solution.With pipette, extract contrast solution 2mL, place the 50mL volumetric flask, add HCl solution (1+3) 2mL successively, KBr solution (250g/L) 2mL, NaNO ₂Solution (70g/L) 2mL covers tight bottle stopper, shakes up, and places 10min; Extract bottle stopper, water flushing bottle stopper and bottle wall add 2mL oxammonium hydrochloride solution (210g/L); Vibration 1-2min treats that bubble disperses, and adds water to scale; Shake up, use the 1cm quartz colorimetric utensil to sentence blank solution in 350nm and be reference, recording absorbance A r is 0.042.

Blank solution: place the 50mL volumetric flask with pipette, extract 2mL water, by above-mentioned reference substance solution assay method operation.

Sample solution is measured: mother liquor is filtered, discard filtrating just, with pipette, extract subsequent filtrate 2mL; Place the 100mL volumetric flask, add water to scale, shake up; Use experimental solutions as the iminodiacetic acid assay, accurate this solution 5mL that draws is in the 50mL volumetric flask, by last method operation; With the blank is reference (sample solution and reference substance solution are operated simultaneously), and recording absorbance A s is 0.013.

Iminodiacetic acid content X4 in the mother liquor, numerical value is represented with g/L, is calculated as follows:

$X_4=\frac{\mathrm{As}\×\frac{m_r}{100}\×2\×c\%\×1000}{\mathrm{Ar}\×\frac{\mathrm{Vs}}{100}\×5}=\frac{0.013\×\frac{0.1220}{100}\×2\×0.98}{0.042\×\frac{2}{100}\×5}\×1000=7.40(g/L)$

Phosphorous acid, phosphoric acid and content of hydrochloric acid in this mother liquor adopt conventional determination of acid-basetitration; To acid base titration after the mensuration employing sodium sulphite addition of content of formaldehyde in the solution.

Embodiment 5

For the accuracy of verifying that analytical approach of the present invention detects each component concentration in the mother liquor, the inventor has done following accuracy validation experiment, and what following content did not have a special instruction is the quality percentage composition:

Get PMIDA (content 98.14%), phosphoric acid (content 85.18%), phosphorous acid (content 99.12%), iminodiacetic acid (content 98.10%), nitrilotriacetic acid (content 99.00%), hydrochloric acid solution (content 156.24g/L) respectively, simulation PMIDA mother liquor composition wiring solution-forming.Accurately claim to such an extent that quality is respectively: PMIDA 6.638g, phosphoric acid 5.352g, phosphorous acid 6.452g, iminodiacetic acid 0.911g, nitrilotriacetic acid 0.076g.Earlier PMIDA, nitrilotriacetic acid, iminodiacetic acid are mixed, accurately add hydrochloric acid solution 50mL, add phosphoric acid, phosphorous acid, heating or sonic oscillation again and make dissolving, be transferred in the 100mL volumetric flask, add water to scale, shake up, as experimental solutions.By the amount that contains above composition in the following mensuration 100mL experimental solutions.

Nitrilotriacetic acid is measured by following method in the mother liquor of above-mentioned preparation:

Instrument: Tianjin, island high performance liquid chromatograph (band UV-detector)

Chromatographic column: InertsilODS-4,250 * 4.5mm, 5 μ m

Moving phase: 0.3%KH ₂PO ₄, use H ₃PO ₄Regulate pH=2.0

Flow velocity: 1.2mL/min

UV：195nm

Sample size: 20 μ L

Standard solution is measured:

(AR, the nitrilotriacetic acid appearance purity of this purchase is 98%) is reference substance with nitrilotriacetic acid, takes by weighing 0.1155g in the 50mL volumetric flask; Add water and make dissolving and be diluted to scale, shake up, accurately draw this solution of 1mL in the 100mL volumetric flask; Add moving phase and be diluted to scale; Shake up, behind the filtering with microporous membrane, sample introduction.The nitrilotriacetic acid peak area is 66128.

Sample determination:

Accurately draw experimental solutions 5mL in the 50mL volumetric flask, add moving phase and be diluted to scale, shake up, the accurate 10mL that draws adds moving phase and is diluted to scale in the 25mL volumetric flask, shakes up, and sample introduction behind the filtering with microporous membrane, nitrilotriacetic acid peak area are 83769.

Nitrilotriacetic acid content X in the mother liquor ₂, numerical value is represented with g/L, is calculated as follows:

$X_2=\frac{\frac{m_r}{50}\×\frac{1}{100}\×\mathrm{Cr}(\%)\×\mathrm{As}}{\frac{V}{50}\×\frac{10}{25}\×\mathrm{Ar}}\×1000=\frac{\frac{0.1155}{50}\×\frac{1}{100}\×0.98\×83769}{\frac{5}{50}\×\frac{10}{25}\×66128}\×1000=0.72(g/L)$ The PMIDA Determination on content is following in the mother liquor of above-mentioned preparation:

In the 100mL volumetric flask, add water to scale with pipette, extract experimental solutions 10mL, shake up; As the experimental solutions of measuring PMIDA content, accurate this solution 3mL that draws adds water 100mL in the 250mL triangular flask; Triethanolamine solution (1+3) 5mL; Borate buffer solution (pH=9.0) 20mL, 3 of arsenazo (III) indicator solutions are with actual concentrations CPb (NO ₃) ₂Pb (the NO of=0.05005mol/L ₃) ₂Standard titration solution titration to solution colour has just become blueness by aubergine, consumes Pb (NO this moment ₃) ₂The volume of standard solution is 1.76mL.

PMIDA content X in the mother liquor ₃, numerical value is represented with g/L, is calculated as follows:

$X_3=\frac{\mathrm{CV}\×227.11}{\frac{V_0}{100}\×V_1}\_X_2\×1.1882=\frac{0.05005\×1.76\×227.1}{\frac{10}{100}\×3}-0.72\×1.1882=65.83(g/L)$

The iminodiacetic acid Determination on content is following in the mother liquor of above-mentioned preparation:

Reference substance solution is measured: get iminodiacetic acid standard model 0.1220g, place the 100mL volumetric flask, add water and make it dissolving, be diluted to scale, shake up, as contrast solution.With pipette, extract contrast solution 2mL, place the 50mL volumetric flask, add HCl solution (1+3) 2mL successively, KBr solution (250g/L) 2mL, NaNO ₂Solution (70g/L) 2mL covers tight bottle stopper, shakes up, and places 10min; Extract bottle stopper, water flushing bottle stopper and bottle wall add 2mL oxammonium hydrochloride solution (210g/L); Vibration 1-2min treats that bubble disperses, and adds water to scale; Shake up, use the 1cm quartz colorimetric utensil to sentence blank solution in 350nm and be reference, recording absorbance A r is 0.042.

Blank solution: place the 50mL volumetric flask with pipette, extract 2mL water, by above-mentioned reference substance solution assay method operation.

Sample solution is measured: experimental solutions is filtered, discard filtrating just, with pipette, extract subsequent filtrate 2mL; Place the 100mL volumetric flask, add water to scale, shake up; Use experimental solutions as the iminodiacetic acid assay, accurate this solution 5mL that draws is in the 50mL volumetric flask, by last method operation; With the blank is reference (sample solution and reference substance solution are operated simultaneously), and recording absorbance A s is 0.015.

Iminodiacetic acid content X4 in the mother liquor, numerical value is represented with g/L, is calculated as follows:

$X_4=\frac{\mathrm{As}\×\frac{m_r}{100}\×2\×c\%\×1000}{\mathrm{Ar}\×\frac{\mathrm{Vs}}{100}\×5}=\frac{0.015\×\frac{0.1220}{100}\×2\×0.98}{0.042\×\frac{2}{100}\×5}\×1000=8.54(g/L)$

The mensuration of phosphoric acid, phosphorous acid and content of hydrochloric acid is following in the mother liquor of above-mentioned preparation:

With pipette, extract experimental solutions 10mL, place the 100mL volumetric flask, add water to scale, shake up, use as hydrochloric acid, phosphoric acid and phosphorous acid assay.With this solution of pipette, extract 5mL; Place the 250mL triangular flask, add water 40mL, 1 of methylate orange indicator solution; Use actual concentrations CNaOH yellow as NaOH standard titration solution titration to the solution becomes of 0.5010mol/L, consuming NaOH standard titration solution volume V1 is 3.98mL; Add 3 of instructions phenolphthalein solutions again, continue titration to solution with the NaOH standard solution and become pink, consume NaOH standard solution cumulative volume V this moment ₂Be 5.50mL; Add neutral CaCl again ₂Solution (200g/L) 10mL shakes up, and becomes pink with NaOH standard solution titration to the solution of actual concentrations CNaOH=0.1010mol/L, consumes NaOH standard solution V ₃Be 3.69mL.

Phosphorus acid content X in the mother liquor ₅, phosphorous acid content X ₆, content of hydrochloric acid X ₇, numerical value is represented with g/L, is calculated as follows respectively:

$X_5=\frac{C_2{V}_3\×98.0}{\frac{V_0}{100}\×V}-X_2\×\frac{98.0}{191.1}-X_3\×\frac{98.0}{227.1}=$

$\frac{0.1010\×3.69\×98.0}{\frac{10}{100}\×5}-0.72\×\frac{98.0}{191.1}-65.83\×\frac{98.0}{227.1}=44.27(g/L)$

$X_6=\frac{C_1(V_2-V_1)\×82.00}{\frac{V_0}{100}\×V}-X_3\×\frac{82.00}{227.1}-X_5\×\frac{82.00}{98.0}=$

$\frac{0.5010\×(5.50-3.98)\×82.00}{\frac{10}{100}\×5}-65.83\×\frac{82.00}{227.1}-44.27\×\frac{82.00}{98.0}=64.07(g/L)$

$X_7=\frac{C_1{V}_1\×36.5}{\frac{V_0}{100}\×V}-X_2\×\frac{72.9}{191.1}-X_3\×\frac{72.9}{227.1}-X_4\×\frac{36.5}{133.1}-X_5\×\frac{36.5}{98.0}-X_6\×\frac{36.5}{82.00}$

$=\frac{0.5010\×3.98\×36.5}{\frac{10}{100}\×5}-0.72\×\frac{72.9}{191.1}-65.83\×\frac{72.9}{227.1}-44.27\×\frac{36.5}{98.0}-8.54\×\frac{36.5}{133.1}-$

$64.07\×\frac{36.5}{82.00}=76.69(g/L)$

Record the content of each composition in the 100mL experimental solutions as stated above, measure result such as following table:

Unit: g

Test item	PMIDA	Phosphoric acid	Phosphorous acid	Iminodiacetic acid	Nitrilotriacetic acid	Hydrochloric acid
							Detect data	6.583	4.427	6.407	0.854	0.072	7.669
Recovery %	101.0	97.1	100.2	95.50	95.7	98.2

It is thus clear that each component content mensuration is scientific and reasonable in the analytical approach of the present invention, the result is accurate.

Claims (5)

1. the analytical approach of a PMIDA mother liquor composition is that the content of formaldehyde, iminodiacetic acid, PMIDA and the nitrilotriacetic acid, phosphorous acid, hydrochloric acid and the phosphoric acid that contain in the PMIDA mother liquor is measured, and it is characterized in that:

The mensuration of said content of formaldehyde is that said mother liquor is filtered, discards filtrating just, draws subsequent filtrate 5mL in container, adds water 50mL; Use magnetic stirrer; With the sodium hydroxide solution neutralization, and use sodium hydrate regulator solution pH=9.20, add sodium sulfite solution 10mL; With the titration of sulfuric acid standard titration solution to pH=9.20, according to

Calculate content of formaldehyde in the mother liquor, in the formula,

Be the actual concentrations mol/L of 0.1mol/L sulfuric acid standard titration solution, V is the consumption mL of 0.1mol/L sulfuric acid standard titration solution, V ₀The cumulative volume mL that representes mother liquor to be measured; Said sodium sulfite solution concentration is 126g/L, and the concentration of sodium hydroxide solution that said neutralization is used is 200g/L, and regulating the used concentration of sodium hydroxide solution of pH=9.20 is 0.1mol/L;

Said to iminodiacetic acid Determination on content in the PMIDA mother liquor, be to get iminodiacetic acid 0.12g earlier, place the 100mL volumetric flask, be dissolved in water and be diluted to scale, shake up, as contrast solution; Draw contrast solution 2mL in the 50mL volumetric flask, add hydrochloric acid solution 2mL successively, potassium bromide solution 2mL, sodium nitrite solution 2mL covers tight bottle stopper; Shake up, place 10min, transfer to bottle stopper, water flushing bottle stopper and bottle wall add 2mL oxammonium hydrochloride solution; Vibration 1-2min treats that bubble disperses, and adds water to scale, shakes up, and uses the 1cm quartz colorimetric utensil to be reference in the 350nm wavelength with blank test; Measure absorbance A r, said blank test be water 2mL in the 50mL volumetric flask, add hydrochloric acid solution 2mL successively, potassium bromide solution 2mL, sodium nitrite solution 2mL; Cover tight bottle stopper, shake up, place 10min, transfer to bottle stopper, water flushing bottle stopper and bottle wall; Add 2mL oxammonium hydrochloride solution, vibration 1-2min treats that bubble disperses, and adds water to scale, shakes up; Carry out PMIDA mother liquor to be measured again and measure, the PMIDA mother liquor is filtered, discard filtrating just; The accurate subsequent filtrate 2mL that draws adds water to scale in the 100mL volumetric flask, shake up; Accurate this solution 2mL that draws by the described operation of last method, is a reference with described blank test in the 50mL volumetric flask; Measure absorbance A s, adjustment extension rate to absorbance is greater than 0.011; Basis then

Calculate the content of iminodiacetic acid in the PMIDA mother liquor, wherein As is a PMIDA mother liquor absorbance to be measured, and Ar is the contrast solution absorbance, m _rBe the quality g of iminodiacetic acid in the contrast solution, C% is the quality percentage composition of iminodiacetic acid in the contrast solution, and Vs is for drawing the volume mL of PMIDA mother liquor to be measured, and Bs is the extension rate of PMIDA mother liquor to be measured, and Br is the extension rate of contrast solution; Said potassium bromide solution concentration is 250g/L, and the mass ratio of hydrochloric acid and water is 1: 3 in the hydrochloric acid solution, and sodium nitrite solution concentration is 70g/L, and the oxammonium hydrochloride solution concentration is 210g/L;

The nitrilotriacetic acid Determination on content is with mother liquor dilution to be measured in the said mother liquor, measures with high performance liquid chromatograph, and nitrilotriacetic acid peak area or peak height and sample size are linear up to being diluted to; With nitrilotriacetic acid is control samples, with its dissolving, dilution, measures with high performance liquid chromatograph, and nitrilotriacetic acid peak area or peak height and sample size are linear up to being diluted to; Through (in the extension rate of the quality of control samples nitrilotriacetic acid * mother liquor to be measured * mother liquor to be measured in the peak area of nitrilotriacetic acid or the peak height * control samples quality percentage composition of nitrilotriacetic acid)/(peak area of nitrilotriacetic acid or peak height in the extension rate * control samples of the volume * control samples of mother liquor to be measured), calculate the content of nitrilotriacetic acid in the mother liquor to be measured;

Said to PMIDA Determination on content in the mother liquor, be that the PMIDA mother liquor is filtered, discard filtrating just, draw subsequent filtrate 10mL in the 100mL volumetric flask; Add water to scale, shake up, draw this solution 3mL in the 250mL triangular flask; Add water 100mL, add triethanolamine solution 5mL, shake up; Add 3 of borate buffer solution 20mL, arsenazo III indicator solutions, just become blueness by aubergine, the consumption of the plumbi nitras standard titration solution that record consumes with plumbi nitras standard titration solution titration to solution colour; Calculate according to PMIDA content (g/L) in the mother liquor then In the formula,

Be the actual concentrations mol/L of 0.05mol/L plumbi nitras standard titration solution, V ₁Be the consumption mL of plumbi nitras standard titration solution, V ₀Be the PMIDA mother liquor volume mL that draws; The volume ratio of triethanolamine and water is 1: 3 in the triethanolamine solution; Said borate buffer solution is to get boric acid 20g; Add water, add mass concentration and be 10% ammoniacal liquor 150mL, using mass concentration again is that 10% ammoniacal liquor is regulated and made pH=9.0; Add water to the solution of 1000mL, said arsenazo III indicator solution is that mass concentration is 0.1% the WS;

Hydrochloric acid, phosphorous acid and phosphorus acid content in the said PMIDA mother liquor are measured, and are that PMIDA mother liquor to be measured is filtered, and the accurate filtrating 10mL that draws is in the 100mL volumetric flask; Add water to scale, shake up, accurate this solution 10mL that draws is in the 250mL triangular flask; Add water 40mL, 1 of methylate orange indicator solution, yellow with NaOH standard titration solution titration to the solution becomes of 0.5mol/L; The volume V1 of the NaOH standard titration solution that record consumes adds 3 of instructions phenolphthalein solutions again, with the NaOH standard titration solution continuation titration of 0.5mol/L; To the solution becomes pink, the cumulative volume V2 of the NaOH standard titration solution that record consumes adds neutral calcium chloride solution 10mL again; Shake up, drip to pink, write down the volume V3 of the NaOH standard titration solution that consumes this moment with 0.1mol/L NaOH standard titration solution; Then according to

Calculate the content of phosphorus acid content in the PMIDA mother liquor, phosphorous acid content and hydrochloric acid respectively, wherein C ₁Be the actual concentrations mol/L of 0.1mol/L NaOH standard titration solution, C is the actual concentrations mol/L of 0.5mol/L NaOH standard titration solution, V ₀For drawing the volume mL of PMIDA mother liquor to be measured; Said methyl orange indicator solution mass concentration 0.1%, said instructions phenolphthalein solution mass concentration is 0.1%, said neutral calcium chloride solution concentration is 200g/L.

2. analytical approach as claimed in claim 1 is characterized in that: the nitrilotriacetic acid Determination on content is accurately to draw PMIDA mother liquor 5mL to be measured earlier in container in the said mother liquor, adds moving phase and is diluted to 50mL; Shake up, drawing wherein, 10mL adds moving phase and is diluted to 25mL in container; Shake up; Behind the filtering with microporous membrane, sample introduction is measured and record aminotriacetic acid peak area with high performance liquid chromatograph; Be control samples with the nitrilotriacetic acid again, get control samples 0.1g, in the 50mL volumetric flask; Ultrasonic concussion dissolving adds water to scale, shakes up; Draw accurately wherein that the said solution of 1.0mL adds moving phase and is diluted to scale in the 100mL volumetric flask, shake up; Behind the filtering with microporous membrane, sample introduction is measured and record aminotriacetic acid peak area with high performance liquid chromatograph; According to be measured

Calculate the content of nitrilotriacetic acid in the PMIDA mother liquor to be measured, m _rBe control samples quality 0.1g, C _rQuality percentage composition % for nitrilotriacetic acid in the control samples; A _rPeak area for nitrilotriacetic acid in the control samples; A _XPeak area for nitrilotriacetic acid in the PMIDA mother liquor to be measured; V is the volume 5mL of PMIDA mother liquor to be measured.

3. according to claim 1 or claim 2 analytical approach, it is characterized in that: the moving phase that adopts in the mensuration of said nitrilotriacetic acid is the phosphate aqueous solution of pH=2～5, or the PBS of pH=2.0; The flow velocity of said moving phase is 0.6～1.5 ml/min.

4. analytical approach as claimed in claim 3 is characterized in that: the chromatographic column that said high performance liquid chromatograph adopts is for 100% water being the liquid spectrum post of moving phase.

5. analytical approach as claimed in claim 4 is characterized in that: said liquid spectrum post is ZORBAXSB-Aq, DIKMA ODS-3 or DIKMA ODS-4.