CN1588008A

CN1588008A - Test paper for detecting water hardness and detecting method

Info

Publication number: CN1588008A
Application number: CN 200410050283
Authority: CN
Inventors: 余萍; 高俊杰; 刘晓兰
Original assignee: Shenyang Polytechnic College
Current assignee: Shenyang Polytechnic College
Priority date: 2004-08-20
Filing date: 2004-08-20
Publication date: 2005-03-02
Anticipated expiration: 2024-08-20
Also published as: CN1265189C

Abstract

The invention provides a test paper and a quantitative test method for the overall hardness of water quality..dippin a test paper into a mixture solution composed of: 0.2-1mg/L complex black T; 0.01-0.05mmol/LDTA magnesium salt; 4-40mL/100ml PH7-11 mixture of sodium tetraborate-sodium hydroxide; 0.5-2g/L ammonium salt; 1-4mg/L of DDTC 5-10 min, airing it dry and plastic sealed with film machine, the test method is:cutting one end of it open and dipping it vertically into the mixture for 5-10min, after reacting with thecalaum ion,megnesium ion to produce a red complex, measuring the height of the red complex, the overall hardness of the water quality is determined The invention has the advantages of accuracy, convenience to operation, strong anti-pollution, etc,it is convenient for long-time preservation and can test quickly the on the spot. The test paper can be applied to testing the overall hardness of a variety of drinking water, boiler water, industrial circulating cooling water, surface water and groundwater.

Description

A kind of test paper and detection method that detects water hardness

Technical field

The invention belongs to water quality inspection technique, particularly a kind of test paper of detection by quantitative determining total hardness of water and detection method.

Background technology

At present, the aspects such as commercial production, environmental monitoring and domestic water that are determined at of determining total hardness of water all are absolutely necessary, and more and more are much accounted of.The general total hardness that adopts methods such as chemical analysis and instrumental analysis to detect water quality, these methods need the analytical control technician of specialty, in the laboratory, have under the conditions such as certain device instrument, vessel and chemical reagent and carry out, and the mensuration process is loaded down with trivial details, time-consuming.The total hardness that adopts test paper method to measure water quality is also arranged, solve the problem of above-mentioned existence.For example the Chinese patent of application number 99111693,3 has been announced " a kind of test paper for determining total hardness of water ", announced " a kind of test paper for detecting total hardness of water and preparation method " with the Chinese patent of application number 01132383,3, but all there is the in use easy contaminated problem of test paper, the part that for example is soaked with water sample can not touch, more can not with other not the test paper plate of usefulness mix and to put, very tight to user's requirement like this, be easy to bring various operate misss; Also exist owing to from a packing, take out wherein a slice test paper, though other test paper usefulness not then, because of contact easily deterioration failure in various degree with air; In addition, because detection is the depth according to the coloring matter color of water sample and test paper reaction generation, perhaps the test paper color is judged determining total hardness of water by blue, blue purple, purplish red variation, this will be owing to the difference of people's naked eyes to the color discrimination ability, and cause the determining total hardness of water test errors greatlyyer, can not satisfy the technical requirement of quantitative measurement.

Summary of the invention

The objective of the invention is to solve the technical matters that adopts existing test paper test determining total hardness of water to exist, provide that a kind of test is accurate, easy to operate, resistance tocrocking is strong, can on-the-spot test paper and detection method of testing determining total hardness of water fast.

Technical essential of the present invention is: Ca in the test paper of detection determining total hardness of water and the water quality ²⁺, Mg ²⁺Generate red fluor-complex, this red material becomes quantitative relationship along the height that test paper rises with determining total hardness of water, because the colour developing of test paper is monochromatic, and be not subjected to the influence of shade, can accurately, fast, conveniently detect the determining total hardness of water value with the height of surveyors' staff quantitative measurement coloring matter; In the test paper mixed liquor, adopted the EDTA disodium magnesium, made the sensitivity of detection not be subjected to Ca in the water sample to be measured ²⁺, Mg ²⁺The influence of concentration ratio, therefore the total hardness value that detects is accurate; Because each sheet test paper all has the plastic packaging film,, be easy to long preservation and use so resistance tocrocking is strong; Test paper color development is monochromatic, just can accurately judge determining total hardness of water according to the length of color, has overcome existing test paper and has judged the big problem of determining total hardness of water error according to change color.

The test paper of detection by quantitative determining total hardness of water of the present invention impregnated in test strips in the mixed liquor earlier, and mixed liquor consists of: network is deceived T0.2～1mg/L; EDTA magnesium salts 0.01～0.05mmol/L; Ammonium salt 0.5～2g/L; PH7～11 sodium tetraborates-sodium hydroxide buffer solution 4～40mL/100ml, the optimum content of the black T of described network is 0.5～0.8mg/L, described pH7～11 sodium tetraborates-sodium hydroxide buffer solution optimum content is 8～32mL/100ml, sodium diethyldithiocarbamate DDTC1～4mg/L, test paper is immersed in the deionized water mixed liquor behind 5～10min, dry or in 50 ℃～80 ℃ dryings through room temperature, carry out the plastic packaging press mold with the press mold machine then, plastic packaging press mold temperature is 110 ℃～130 ℃, and described test strips is the chromatography filter paper bar of long 35～50mm, wide 3～6mm.

The method of detection by quantitative determining total hardness of water of the present invention is: test paper one end of plastic packaging cut off, vertically inserted in the water sample to be detected, and through 5～10min, Ca in the water then ²⁺, Mg ²⁺Generate red complex along test paper rising certain altitude and with test paper, this red complex has quantitative relationship along the height and the water hardness that test paper rises, and measures the height that develops the color with the determining total hardness of water surveyors' staff then and comes quantitative measurement determining total hardness of water value.

The test paper of detection by quantitative determining total hardness of water of the present invention and detection method can be measured water hardness exactly, to the water hardness (in calcium) of 10mg/L, are 4.93% through 11 its relative standard deviations of replicate determination (RSD).Detecting of this test paper is limited to 0.7mg/L (in calcium).Can accurately measure the above water hardness of 1mg/L (in calcium; If in lime carbonate, then measure on duty 2.5).

The present invention have detect accurate, easy to operate, resistance tocrocking is strong, can on-the-spotly test excellent Dian such as determining total hardness of water fast, test paper color development is monochromatic, length according to colour developing just can accurately be judged determining total hardness of water, has overcome existing test paper and has judged the big problem of determining total hardness of water error according to the depth of color or according to color by blue, blue purple, purplish red variation.This test paper is applicable to measures various potable water, boiler feed water, industrial recirculated cooling water, the day water and phreatic hardness.Assay method is simple, directly perceived, and the test paper preparation cost is low, is easy to long-time preservation, is easy to carry, and can carry out on-site measurement.

Embodiment

Further specify technical scheme of the present invention and detection method below in conjunction with example.

1, the preparation of test paper

Earlier chromatography filter paper is cut into the test strips of long 50mm, wide 6mm, test strips be impregnated in the mixed liquor, mixed liquor consists of: network is deceived T0.3mg/L; EDTA magnesium salts 0.035mmol/L; Ammonium salt 1.5g/L, pH10 sodium tetraborate-sodium hydroxide buffer solution 10ml, sodium diethyldithiocarbamate DDTC 2mg/L is diluted to 100ml with deionized water; Test paper is immersed in taking-up after 5～10 seconds in the mixed liquor; Dry or in 70 ℃ of dryings through room temperature again; Carry out the plastic packaging press mold with the press mold machine then, plastic packaging press mold temperature is 110 ℃.

2, the method for detection by quantitative determining total hardness of water

Test paper one end of plastic packaging is cut off, vertically inserted in the water sample to be detected, through 5min, then Ca in the water ²⁺, Mg ²⁺Generate red complex along the test paper rising and with test paper, measure the height of red material then with the determining total hardness of water surveyors' staff, can quantitative measurement determining total hardness of water value.If hardness exceeds 100mg/L (in calcium), for accurate mensuration can be measured water sample after the deionized water dilution again.

3. test paper method and EDTA titrimetry compare, and be as shown in table 1:

Table 1

In calcium in lime carbonate

Relatively by mistake

EDTA EDTA

The test paper method test paper method is poor

The titrimetry titrimetry

(％)

Dongling tap water 45 45.7 112.5 114.2-1.5

Big eastern tap water 100 100.8 250 252-0.8

Emperor's aunt tap water 70 68.6 175 171.5 2.0

Peace tap water 40 39.2 100 98 2.0

Iron west tap water 50 51.5 125 128.8-2.9

Nan Canal water 34 33.2 85 83 2.4

Canal, north water 30 29.1 75 72.8 3.1

Certain mineral water 5 5.02 12.5 12.6 0.4

Annotate: 1. in the data of lime carbonate for to take advantage of 2.5 to obtain in the data of calcium.

2. water sample picks up from the resident of Shenyang City respectively and uses tap water and canal, north and south, city water.

Claims

1, a kind of test paper of quantitative measurement determining total hardness of water is characterized in that, earlier test strips be impregnated in the mixed liquor, and mixed liquor consists of: network is deceived T 0.2～1mg/L; EDTA magnesium salts 0.01～0.05mmol/L; PH7～11 sodium tetraborates-sodium hydroxide buffer solution 4～40mL/100ml; Ammonium salt 0.5～2g/L; Sodium diethyldithiocarbamate DDTC 1～4mg/L; Test strips is immersed in the deionized water mixed liquor behind 5～10min, dries or in 50 ℃～80 ℃ dryings through room temperature again.

2, the test paper of detection by quantitative determining total hardness of water according to claim 1 is characterized in that described pH7～11 sodium tetraborates-sodium hydroxide buffer solution optimum content is 8～32mL/100ml.

3, the test paper of detection by quantitative determining total hardness of water according to claim 1 is characterized in that the optimum content of the black T of described network is 0.5～0.8mg/L.

4, the test paper of detection by quantitative determining total hardness of water according to claim 1 is characterized in that described test strips after drying carries out the plastic packaging press mold with the press mold machine, and plastic packaging press mold temperature is 110 ℃～130 ℃.

5, the test paper of detection by quantitative determining total hardness of water according to claim 1 is characterized in that the chromatography filter paper bar of described test strips for long 35～50mm, wide 3～8mm.

6, a kind of detection method of detection by quantitative determining total hardness of water is characterized in that, detection method is:

(1) test paper one end of plastic packaging is cut off;

(2) test paper is cut off 5～10min in the vertical insertion of the end water sample, take out then;

(3) measure Ca in test paper and the water with the determining total hardness of water surveyors' staff ²⁺, Mg ²⁺Generate the height of red complex, quantitative measurement determining total hardness of water value.