Summary of the invention
The present invention one of is intended to solve the problems of the technologies described above at least to a certain extent or at least provides a kind of useful business to select.
For this reason, one object of the present invention is to propose a kind of method with detecting lead ion in water quality.
According to the method for detection of lead ion in water of the embodiment of the present invention, comprise the following steps:
Measure screening agent solution, chromogenic reagent solution and damping fluid; In water sample to be detected, add successively described screening agent solution, chromogenic reagent solution and damping fluid and mix, obtaining test samples; And the absorbance of test samples described in use spectrophotometer measurement, and calculate the lead content in described water sample to be detected, wherein, in described chromogenic reagent solution, the mass volume ratio of developer and solvent is (0.05 ~ 5g): 1L, stating developer is Fluorone reagent series developer, described damping fluid is borate buffer solution, in described screening agent solution, contains screening agent, water and hydrochloric acid.
The present invention adds concentrated hydrochloric acid in screening agent solution, can under the condition that does not affect reagent pH value, better preserve reagent, is conducive to reduce reagent waste, has saved resource.
Wherein, described screening agent can be in sodium citrate, disodium ethylene diamine tetraacetate, 1,10-ferrosin, oxammonium hydrochloride any one or multiple, wherein, especially preferably 1,10-ferrosin.Through the inventor's large quantity research discovery, these screening agents can both be sheltered heavy metal well, thereby can effectively improve plumbous selectivity.
In addition, preferably, described pack is (0.5 ~ 5g) with the mass volume ratio of screening agent and water in screening agent solution: (0.5 ~ 3) L; Further preferably, described pack is (0.5 ~ 2g) with the mass volume ratio of screening agent and water in screening agent solution: (0.5 ~ 2) L; Especially preferably, described pack is 1.5g:1L with the mass volume ratio of screening agent and water in screening agent solution.
Preferably, the concentrated hydrochloric acid that the described pack that is 1000ml in total amount is 37% by the mass concentration that has added 0.5 ~ 5ml in screening agent solution.If the addition of hydrochloric acid is too much, the easy pH value of medium when impact test, and if the addition of hydrochloric acid is too low, be difficult to the effect of the stability that plays increase screening agent solution.
Described Fluorone reagent series developer comprises DBH-PF or phenylfluorone, in described chromogenic reagent solution, can also contain sensitizer, and described sensitizer is cetyl trimethyl ammonium bromide.
Preferably, use plumbous standard water solution value and described screening agent solution, chromogenic reagent solution and damping fluid to mix and measure absorbance, to draw lead solution standard absorbance curve, and by the absorbance of described test samples and described standard absorbance curve are compared to calculate the lead content in described water sample to be detected.
Preferably, the volume ratio of described water sample to be detected and screening agent solution, chromogenic reagent solution and damping fluid is (5 ~ 15): (1 ~ 2): (1 ~ 2): (1 ~ 2).
Preferably, the volume ratio of described screening agent solution, chromogenic reagent solution and damping fluid is (1 ~ 2): (1 ~ 2): (1 ~ 2).
Preferably, the volume ratio of described screening agent solution, chromogenic reagent solution and damping fluid is 1:1:1.
Additional aspect of the present invention and advantage in the following description part provide, and part will become obviously from the following description, or recognize by practice of the present invention.
Embodiment
Describe embodiments of the invention below in detail.It should be noted that, embodiment described below is exemplary, is intended to for explaining the present invention, and can not be interpreted as limitation of the present invention.
first, pack screening agent solution and preparation method thereof is described.
According to the pack of the embodiment of the present invention with containing screening agent, water and hydrochloric acid in screening agent solution.
The present invention adds concentrated hydrochloric acid in screening agent solution, can under the condition that does not affect reagent pH value, better preserve reagent, is conducive to reduce reagent waste, has saved resource.
Wherein, described screening agent can be in sodium citrate, disodium ethylene diamine tetraacetate, 1,10-ferrosin, oxammonium hydrochloride any one or multiple, wherein, especially preferably 1,10-ferrosin.Through the inventor's large quantity research discovery, these screening agents can both be sheltered heavy metal well, thereby can effectively improve plumbous selectivity.
In addition, preferably, described pack is (0.5 ~ 5g) with the mass volume ratio of screening agent and water in screening agent solution: (0.5 ~ 3) L; Further preferably, described pack is (0.5 ~ 2g) with the mass volume ratio of screening agent and water in screening agent solution: (0.5 ~ 2) L; Especially preferably, described pack is 1.5g:1L with the mass volume ratio of screening agent and water in screening agent solution.
Preferably, the concentrated hydrochloric acid that the described pack that is 1000ml in total amount is 37% by the mass concentration that has added 0.5 ~ 5ml in screening agent solution.If the addition of hydrochloric acid is too much, the easy pH value of medium when impact test, and if the addition of hydrochloric acid is too low, be difficult to the effect of the stability that plays increase screening agent solution.
, it should be noted that herein, both can in prefabricated industry, add 37% concentrated hydrochloric acid, also can add as the case may be the hydrochloric acid of variable concentrations, as long as reset most after appearance, the concentration of described hydrochloric acid meets above-mentioned scope.
Preparation method according to the pack of the embodiment of the present invention with screening agent solution, comprises the steps:
A) take screening agent;
B) described screening agent is dissolved in to pure water, obtains prefabricated solution; And
C) in described prefabricated solution, add hydrochloric acid, obtain described pack screening agent solution.
Wherein, preferably, described pack is with in screening agent solution, and described pack is (0.5 ~ 5g) with the mass volume ratio of screening agent and water in screening agent solution: (0.5 ~ 3) L; Further preferably, described pack is (0.5 ~ 2g) with the mass volume ratio of screening agent and water in screening agent solution: (0.5 ~ 2) L; Especially preferably, described pack is 1.5g:1L with the mass volume ratio of screening agent and water in screening agent solution.
next, describe pack for detection of lead ion in water quality and preparation method thereof.
According to the pack for detection of lead ion in water quality of the present invention, comprise screening agent solution, chromogenic reagent solution and damping fluid.
Wherein, described screening agent solution is the screening agent solution according to above-mentioned arbitrary embodiment, does not repeat them here.
In addition, the screening agent solution of the embodiment of the present invention is suitable for combining with xylenol orange chromogenic reagent solution, porphin series solution, Fluorone reagent series chromogenic reagent solution, peacock green chromogenic reagent solution and azo chromogenic reagent solution, for detecting lead ion in water quality.
for inhomogeneity chromogenic reagent solution, its composition and configuration method is described respectively below.
a) xylenol orange (XO)
Xylenol orange is a kind of very important spectrophotometric color reagent in microanalysis, and in phosphoric acid 2 acetic acid 2 borate buffer solutions of pH 6. 0, xylenol orange forms 1: 1 stable red complex with lead, causes the enhancing of absorbance.
XO chemical name is 3,3 '-bis-[N, N-bis-(ethyloic) amino methyl]-o-cresol sulfonphthalein, is a kind of sulfonephthalein ammonia carboxylic metallochromic indicator the most conventional in metallic ion analytic process.
XO has different chelating system (Chelating System) to exist under different acid-base conditions, therefore in the time of metallic ion and XO formation chelate, also can carry out in a different manner chelating.
In p H=1~6 o'clock, in aqueous solution, XO molecule is mainly with H
5l
-and H
4l
2-existing, should be H in the main existence form of p H=6 o'clock XO
4l
2-, H
5l
-and H
4l
2-.
The absorbance of solution to be measured raises and increases with p H value, considers sensitivity and the reagent of measuring
The impact of the factors such as blank light absorption value, finally selects that p H=6. 0 is suitable reaction condition.
In addition, using phosphoric acid-acetic acid-borate buffer solution (pH 6. 0).This buffer solution forms by phosphoric acid, boric acid and acetic acid mixed preparing that concentration is 0. 04 mol/L, when use, is adjusted to pH 6. 0 with 0. 2 mol/L NaOH solution on acidometer.
b) porphin series
Porphyrin reagent is because its special optical property becomes a kind of very promising organicvisualization reagent.As organicvisualization reagent, porphyrin has the sensitivity of superelevation, and its molar absorptivity is up to 1 × 10
5~6 × 10
5l mol
-1cm
-1, therefore, the research of measuring heavy metal ion using porphyrin reagent as developer has caused numerous scientific workers' extensive concern.In the present invention, utilize porphyrin easily to generate the chemical characteristic of 1: 1 high stability complex with plumbous (II), porphyrin reagent is applied to the lead content detecting in water quality.
In described chromogenic reagent solution, the mass volume ratio of developer and solvent is (0.05 ~ 5g): 1L, and described developer is porphin series, and described solvent is (N, N-dimethyl formamide).
In addition, described porphin series comprises: four (4-methoxyphenyl) porphyrin, four (4 chloro-3 sodium sulfonate phenyl) porphyrin, four (2,5-difluorophenyl) porphyrin, four (3-hydroxy phenyl) porphyrin, four (2,5-difluorophenyl) porphyrin, four (the bromo-4-hydroxy benzenes of 3,5-bis-) porphyrin, four (4-sulfonic benzo) porphyrin, P tetra-(4-pyridine) porphyrin etc.Wherein, above-mentioned porphin series can be used separately, also can multiple merging use.
In addition, in described chromogenic reagent solution, can also contain catalyzer, described catalyzer comprises at least one in oxammonium hydrochloride salt, oxine, sodium fluoride-Citrate-ethylene diamine, phenanthroline, ascorbic acid.
In addition, in the time using porphin series solution, can use borate buffer solution, and medium pH is adjusted under weak basic condition, for example chromogenic reaction is carried out in left and right, pH9 ~ 10.5.
c) Fluorone reagent series developer
Fluorones reagent is a kind of common metallic ion developer, utilize fluorone reagent to carry out the conditional request of lead (II) assay simple, under alkaline medium, room temperature, just can complete rapidly the complexing chromogenic reaction of lead (II) and phenylfluorone reagent, color development system is stable, and adds surfactant to have stronger sensitization to system.
For example, can in borate buffer medium, utilize plumbous (II) and DBH-PF cetyl trimethyl ammonium bromide (CTMAB) exist the lower principle that forms red complex measure water quality in the content of lead (II).Can also be in the medium solution that p H value is 12.5~13.3, the complex anion of Pb (II) and phenylfluorone and the kation that cetyl trimethyl ammonium bromide ionizes out form hyacinthine ternary complex, can be in 0~8.0 μ g/ 25mL concentration range Accurate Determining micro lead (II) content.
As Fluorone reagent series developer, can enumerate 5/-2 nitro salicyl fluorone, trimethoxy fluorone, adjacent chloro phenylfluorone (
σ-cPF), O-Nitrophenylfluorone fluorone (
σ-nPF) etc.Wherein, above-mentioned Fluorone reagent series developer can use separately, also can multiple merging use.
In addition, in described chromogenic reagent solution, the mass volume ratio of developer and water is (0.05 ~ 5g): 1L).
In addition, in the time using Fluorone reagent series developer, can use borate buffer solution, and medium pH is adjusted under weak basic condition, for example chromogenic reaction is carried out in left and right, pH9 ~ 10.5.
d) peacock green
Pb
2+can form complex with MG-KI, the absorbance of complex and Pb
2+concentration is relevant.Research shows, pH 4. 0 o'clock, Pb2+-MG-KI at room temperature can form rapidly stable complex, complex in the absorbance at 618nm place with Pb
2+concentration increases and declines, and plumbous concentration is at 0. 4-2. 8mg/ L
Scope and negative absorbance are good linear relationship, and molar absorptivity is 6. 5 × 10
4lmol
-1cm
-1.relative deviation is 2. 5 % (n=11).The method is highly sensitive, and favorable reproducibility is easy and simple to handle, analysis speed is fast, is suitable for the Fast Measurement of industrial wastewater.
Described damping fluid can be acid hexamethylenetetramine buffer solution.
e) azo developer
Under strong acidic condition, plumbous (II) can make Azo-reagents fade, and absorbance and lead (II) concentration are linear dependence within the specific limits.
Conventional Azo-reagents has that Arsenazo, azo chlorine are Phosphorus, azochlorosulfonate class, azo sulphur class etc., wherein conventional with Arsenazo.
Because color development system need be carried out under strong acidic condition, therefore utilize the selectivity of arsennazo group reagents mensuration plumbous (II) stronger, this is conducive to useless trace lead in water (II) and measures.For example, the chromogenic reaction of Dibromo-p-chloro carboxyazo arsine and micro lead (II), this method selectivity can allow by force the interfering ions such as a large amount of copper, zinc, aluminium to exist; Taking dibromo to methyl bromide azo sulphur (DB-MBSA) as developer, measure plumbous (II) content at 638 nm wavelength places, method antijamming capability is strong, except Ca (II) and Ba (II), other ions all do not produce interference, and can adopt potassium iodide-methyl isobutyl ketone (KI-MI-B K) extraction to eliminate interference for Ca (II) and Ba (II) interfering ion.
finally, the method for detection of lead ion in water is described.
Use the pack of above-mentioned any embodiment, can be used for detecting the content of the lead ion in water quality.
According to the method for detection of lead ion in water of the embodiment of the present invention, comprise the following steps:
Measure screening agent solution, chromogenic reagent solution and damping fluid;
In water sample to be detected, add successively described screening agent solution, chromogenic reagent solution and damping fluid and mix, obtaining test samples; And
The absorbance of test samples described in use spectrophotometer measurement, and calculate the lead content in described water sample to be detected.
Use plumbous standard water solution value and described screening agent solution, chromogenic reagent solution and damping fluid to mix and measure absorbance, to draw lead solution standard absorbance curve, and by the absorbance of described test samples and described standard absorbance curve are compared to calculate the lead content in described water sample to be detected.
Preferably, the volume ratio of described water sample to be detected and screening agent solution, chromogenic reagent solution and damping fluid is (5 ~ 15): (1 ~ 2): (1 ~ 2): (1 ~ 2); Further preferably, the volume ratio of described screening agent solution, chromogenic reagent solution and damping fluid is (1 ~ 2): (1 ~ 2): (1 ~ 2); The volume ratio of especially preferred described screening agent solution, chromogenic reagent solution and damping fluid is 1:1:1.
With in prior art, must, with compared with abstraction technique, according to detection method of the present invention, avoid using the contour toxic organic solvent of methenyl choloride extract the harm and the environmental pollution that bring, easy to be quick, measurement result is accurate, more friendly to environment.
Below, describe in detail according to the pack of the embodiment of the present invention and use the detection method of this pack by preferred embodiment.
Wherein, taking developer as xylenol orange, buffer agent solution is that example describes detection method as phosphoric acid-acetic acid-borate buffer solution, screening agent as 1,10-ferrosin.For the situation of pack that uses other embodiment, except the composition difference of pack, can adopt identical method to detect, description is omitted herein.
Embodiment 1
The raw materials that is used for the pack of monitoring lead ion is: 1,10-ferrosin that purity is AR, the xylenol orange that purity is AR, the acid hexamethylenetetramine that purity is AR, concentrated hydrochloric acid and the pure water that mass concentration is 37%.
The preparation of screening agent solution: take a certain amount of acid hexamethylenetetramine buffer solution, add a small amount of pure water to dissolve, in 1000ml volumetric flask, add 1.5ml concentrated hydrochloric acid, use pure water constant volume, mix for subsequent use.Wherein, in described screening agent solution, the mass volume ratio of screening agent and water is 1.5g:1L.
The preparation of chromogenic reagent solution: accurately take a certain amount of xylenol orange and be dissolved in pure water, be stirred to completely and dissolve, then add pure water, be settled to 1000ml, mix, be kept in brown volumetric flask for subsequent usely, the mass volume ratio of described developer and pure water is 1.5g:1L.
The preparation of buffer solution: take a certain amount of phosphoric acid-acetic acid-boric acid and be dissolved in pure water, add acid that pH is adjusted to 6, shake up, then add pure water, be settled to 1000ml, shake up, for subsequent use.
The drafting of typical curve: accurately pipette plumbous standard solution that 0,5,10,15,20,25,30,35,40,45,50 ml concentration are 20mg/L in 100ml volumetric flask, add 1ml screening agent, solution is fully mixed, after adding 1 ml developer, solution is fully mixed, add again 1ml damping fluid, fully shake up, after a few minutes, taking reagent blank as reference, 30 mm cuvettes, absorbance is measured at certain wavelength place, and drawing standard curve.
Embodiment 2
By a certain amount of target actual water sample that adds of Tianrui's online water quality lead ion monitor automatic sucking, automatic sucking screening agent solution successively again, chromogenic reagent solution, buffer soln, by automatic mixing, after 5 minutes, taking reagent blank as reference, the cuvette of 30 mm light paths, measures absorbance at 535nm wavelength place, the result of measuring for six times is respectively 1.548,1.597,1.604,1.626,1.580,1.615, and relative standard deviation RSD is 1.7%.
From the present embodiment, the pack monitoring lead ion of monitoring lead ion prepared by employing the present invention, measured result precision, accuracy are all fine, have solved the error residual brought due to auto injection pipeline.
Embodiment 3
By a certain amount of actual water sample of Tianrui's online water quality lead ion monitor automatic sucking, automatic sucking screening agent solution successively again, chromogenic reagent solution, buffer soln, by automatic mixing, after 10 minutes, taking reagent blank as reference, the cuvette of 30mm light path, measures absorbance at 535nm wavelength place, the result of measuring for six times is respectively 0.092,0.086,0.088,0.084,0.084,0.088,0.088, and relative standard deviation is 0.0028.
From the present embodiment, adopt agents useful for same of the present invention and water sample that proportioning is surveyed to detect lower limit and be low to moderate 0.1mg/L, reach GB requirement.
In the description of this instructions, the description of reference term " embodiment ", " some embodiment ", " example ", " concrete example " or " some examples " etc. means to be contained at least one embodiment of the present invention or example in conjunction with specific features, structure, material or the feature of this embodiment or example description.In this manual, the schematic statement of above-mentioned term is not necessarily referred to identical embodiment or example.And specific features, structure, material or the feature of description can be with suitable mode combination in any one or more embodiment or example.
Although illustrated and described embodiments of the invention above, be understandable that, above-described embodiment is exemplary, can not be interpreted as limitation of the present invention, those of ordinary skill in the art can change above-described embodiment within the scope of the invention in the situation that not departing from principle of the present invention and aim, amendment, replacement and modification.