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CN-121994730-A - Prefabricated liquid for measuring total iron in water, preparation method and measuring method

CN121994730ACN 121994730 ACN121994730 ACN 121994730ACN-121994730-A

Abstract

The invention discloses a prefabricated liquid for measuring total iron in water, a preparation method and a measuring method, and belongs to the technical field of water quality detection, wherein each 1000mL of prefabricated liquid comprises 45mL-55mL of concentrated hydrochloric acid, 9g-11g of hydroxylamine hydrochloride, 0.12g-0.18g of phenanthrazine, acetic acid-sodium acetate buffer salt for adjusting the pH value of a final system to 4.5+/-0.2 and the balance of deionized water. The invention provides a chemically stable single-solution prefabricated reagent, which is characterized in that a strong acid extracting agent, a high-efficiency reducing agent and an iron ion color developing agent are premixed into a whole, and through a specific buffer-stable system design, the premixed reagent maintains extremely low pH value to keep stability when being stored, and when a water sample is added for dilution, the pH value of the system automatically rises to a color developing required range, so that the automatic continuous execution of acidolysis, reduction and color development three-step reaction is realized. The corresponding measurement method is extremely simple.

Inventors

  • PEI CHUNLING
  • HE BINBIN
  • YANG ZHUOYAN
  • WANG SHUOYAO
  • GUO YUJING
  • LI WEI
  • LI YANFEI
  • LI CHENGLONG

Assignees

  • 天津铁厂有限公司

Dates

Publication Date
20260508
Application Date
20251224

Claims (10)

  1. 1. A pre-cast solution for use in an in-water total iron assay, comprising per 1000mL of pre-cast solution: 45mL-55mL of concentrated hydrochloric acid; 9g-11g of hydroxylamine hydrochloride; 0.12g-0.18g of phenanthroline; To adjust the final system pH to 4.5±0.2; the balance of deionized water.
  2. 2. The prefabricated liquid for determination of total iron in water according to claim 1, wherein concentrated hydrochloric acid is 50.0mL, hydroxylamine hydrochloride is 10.0g, and phenanthrazine is 0.15g.
  3. 3. A method for preparing a prefabricated liquid for measuring total iron in water, which is characterized in that each 1000mL of prefabricated liquid comprises the following steps: S101, placing a plastic beaker containing 800mL of deionized water on a magnetic stirrer, and starting magnetic stirring; s102, adding 45-55 mL of concentrated hydrochloric acid; S103, adding 9-11 g of hydroxylamine hydrochloride solid, and continuously stirring until the solid is completely dissolved, so that the solution is clear; S104, adding 0.12g-0.18g of phenanthroline solid, and continuously stirring for more than 30 minutes to completely dissolve the color-developing agent; s105, adding acetic acid-sodium acetate buffer salt; S106, the volume is fixed to 1000mL by deionized water, and the materials are fully and uniformly mixed.
  4. 4. The method for preparing a prefabricated liquid for measuring total iron in water according to claim 3, further comprising S106, dispensing 5.00mL each into a transparent or brown glass/plastic tube with a rubber plug or screw cap sealing cover.
  5. 5. The prefabricated liquid for determination of total iron in water according to claim 3, wherein the concentrated hydrochloric acid solid is 50.0mL, hydroxylamine hydrochloride solid is 10.0g, and phenanthrazine solid is 0.15g.
  6. 6. The method for preparing a prefabricated liquid for use in total iron determination in water according to claim 3, wherein S101 comprises placing a 2000mL plastic beaker containing 800mL deionized water on a magnetic stirrer in a fume hood, turning on magnetic stirring, and setting the rotation speed to 300rpm.
  7. 7. The method for preparing a prefabricated liquid for use in water ferroelectricity according to claim 6, wherein S103 includes adding 9g-11g of hydroxylamine hydrochloride solid, increasing the stirring speed to 600rpm, and continuing stirring for 15 minutes-20 minutes until the solid is completely dissolved, and clarifying the solution.
  8. 8. A method for determining total iron in water, comprising: S1, adding the prefabricated liquid in the claim 1 or 2 into a sample to be detected according to a preset volume ratio; s2, uniformly mixing, and reacting for 10 minutes at room temperature; S3, measuring absorbance at 562nm wavelength; S4, calculating the original concentration according to a standard curve.
  9. 9. The method for total iron determination in water according to claim 8, characterized by being divided into, based on the range of iron concentrations: The standard mode is suitable for water samples with the iron concentration of 0.01mg/L-10mg/L, 10.0mL of samples are taken, and 5.0mL of prefabricated liquid is added; The expansion mode is suitable for water samples with the iron concentration of 2mg/L-50mg/L, 5.0mL of samples are taken, deionized water is diluted to 10mL, and 5.0mL of prefabricated liquid is added.
  10. 10. The method for measuring total iron in water according to claim 8, further comprising the step of drawing a standard curve, wherein the standard curve is drawn by adopting the same volume proportion, preparing standard iron series with different concentrations by deionized water for color development, and the correlation coefficient R2 is more than or equal to 0.99.

Description

Prefabricated liquid for measuring total iron in water, preparation method and measuring method Technical Field The invention belongs to the technical field of water quality detection, and particularly relates to a prefabricated liquid for measuring total iron in water, a preparation method and a measuring method. Background The total iron concentration in water is one of the important indexes for evaluating water quality, judging pipeline corrosion condition and monitoring industrial pollution degree. At present, the technology for detecting iron in water mainly faces the following technical bottlenecks and demands in practical application: The multi-component coexistence-inhibition difficult problem is that three core reagents, namely a reducing agent, a buffering agent and a color developing agent, are sequentially introduced in the conventional iron ion color developing detection method. The three are difficult to coexist simultaneously in a single stable solution system because the final reaction needs to be carried out under a weak acidic condition, and under the environment, the reducing agent is easy to oxidize and the color developing agent is easy to degrade, so that the stability of the reagent is obviously reduced. The operation is complicated and the error is accumulated, according to the standard detection flow, an acidic reducing agent is needed to be added to pretreat the water sample, then a buffering agent is added to adjust the pH value, and finally a color developing agent is introduced to react. The multi-step operation has the advantages of complex flow, long time consumption, and obvious human error caused by multiple reagent addition and reaction condition control, and influences on the accuracy and repeatability of the result. The contradiction between the cost and the stability of the reagent is that the current commercial reagent kit usually adopts split packaging to relieve the mutual interference and the stability of the reagent, but the cost of packaging and materials is increased, and the space requirement for transportation and storage is increased. In addition, the terminal user needs to execute multi-step preparation and sample adding operation every detection, which is not beneficial to quick screening and real-time monitoring in the field or emergency environment. Therefore, there is an urgent need in the industry to develop a prefabricated solution, a preparation method and a determination method for determining total iron in water, which can be prepared under normal temperature conditions and integrate three functions of reduction, color development and buffering, so as to overcome the limitations of the existing methods in terms of operability, stability, applicability and the like, and improve the efficiency and reliability of iron ion detection. Disclosure of Invention The invention aims to provide a prefabricated liquid for measuring total iron in water, a preparation method and a measuring method, and aims to solve the technical problems of complicated heating digestion, multiple steps and long time consumption of the traditional total iron measuring method. To achieve the above object, a first object of the present invention is to provide a prefabricated liquid for determination of total iron in water, comprising, per 1000mL of prefabricated liquid: 45mL-55mL of concentrated hydrochloric acid; 9g-11g of hydroxylamine hydrochloride; 0.12g-0.18g of phenanthroline; To adjust the final system pH to 4.5±0.2; the balance of deionized water. Preferably, the concentrated hydrochloric acid is 50.0mL, hydroxylamine hydrochloride is 10.0g, and phenanthroline is 0.15g. A second object of the present invention is to provide a method for preparing a pre-cast liquid for determination of total iron in water, comprising, per 1000mL of pre-cast liquid: S101, placing a plastic beaker containing 800mL of deionized water on a magnetic stirrer, and starting magnetic stirring; s102, adding 45-55 mL of concentrated hydrochloric acid; S103, adding 9-11 g of hydroxylamine hydrochloride solid, and continuously stirring until the solid is completely dissolved, so that the solution is clear; S104, adding 0.12g-0.18g of phenanthroline solid, and continuously stirring for more than 30 minutes to completely dissolve the color-developing agent; s105, adding acetic acid-sodium acetate buffer salt; S106, the volume is fixed to 1000mL by deionized water, and the materials are fully and uniformly mixed. Preferably, the method further comprises S106, dispensing 5.00mL each into transparent or brown glass/plastic tubes with rubber plugs or screw cap sealing covers. Preferably, the concentrated hydrochloric acid solid is 50.0mL, the hydroxylamine hydrochloride solid is 10.0g, and the phenanthrazine solid is 0.15g. Preferably, S101 comprises placing a 2000mL plastic beaker containing 800mL deionized water in a fume hood on a magnetic stirrer, turning on magnetic stirring, and setting the rotational speed