Besides silver nitrate, what other reagents can detect chloride ions?

In fact, it is mainly the detection of ag+

The following cited papers

Determination of chloride ion by molar method

The range of determination of chloride ion by molar method is = 5 ~ 111 mg/L. Zhou Shaoling et al. [2] theoretically pointed out that potassium chromate was used as an indicator, and the titration experiment was carried out with silver nitrate standard solution under neutral or weakly alkaline conditions. Due to the loss of AgCl precipitation and dissolution, 1.44 mg/L chloride ion remained in the solution could not be titrated. Therefore, the determination of water quality with low chloride ion content by molar method will cause greater analysis error and poor determination precision. In the process of titration of chloride ion with AgNO _ 3, Ag+ easily forms Ag (NH _ 3)+with ammonia in the solution, which increases the consumption of AgNO _ 3 and leads to high analytical results. Therefore, the pH value of the solution should be controlled to be neutral when determining the chloride ion content in the water by molar method. Zhou Qiang et al. [3] used the seedlings of barley variety Jian 4 with strong salt tolerance as materials, and determined the chloride ion content in plants by silver nitrate titration. The results show that the linear relationship is good in the range of 1~1.5 mol/L, and the correlation coefficient r is 1.9986, but the standard curve does not pass through the coordinate origin. The recovery rate was 87.73% ~117.78%, and the RSD was 11.81%. The accuracy is only 88.43% and the coefficient of variation < P > is 11.33%.

Molar method is a traditional method of measuring

, but it is more accurate to measure only substances with high chloride content

. Potassium chromate and silver nitrate reagents used in this method are toxic substances, and

discharged into the environment will cause environmental pollution.

The high price of silver nitrate reagent increases the cost of determination

and affects the practicability of the method.

2.2

Spectrophotometry

Spectrophotometry is a method for qualitative and quantitative analysis of the measured

substance by measuring its light absorption at a specific wavelength or within a certain wavelength

Yang Xuefen [4]

The content of

chloride ion in industrial phosphorous acid was determined by

spectrophotometry with hydrogen peroxide as oxidant and nitric acid -

glycerol as medium. The system has high stability

, the detection wavelength is 381 nm, the content of chloride ion

is linear in the range of 1~6 g/mL

, the correlation coefficient is 1.9999, and the recovery rate of

is 96%~115%.

Guan Rui et al [5]

By studying the stability

of silver chloride precipitation in gelatin -

ethanol aqueous solution, a

spectrophotometric analysis method for the determination of trace chloride ions was established and applied to the determination of trace chloride ions in process water with

machine.

under the optimum experimental conditions, the chloride ion concentration

showed good linearity in the range of 1~6 mg/L

, the correlation coefficient was 1.9993, the standard

deviation of the method was 1.118, the coefficient of variation was

1.126, and the recovery rate was 1.111% ~ 1.15%. The detection limit of this

method is 1.35× 11

-2

mg/L.

gu ligong [6]

an indirect spectrophotometric method for the determination of

mercury thiocyanate -

ferric nitrate was established by using the reaction of

chloride ions with mercury thiocyanate to generate a slightly

ionized mercury chloride complex under acidic conditions, and releasing an equal

amount of thiocyanate radical to react with iron (III) to generate a

red complex.

This method has high sensitivity and good reproducibility. The method is simple and rapid, and can be used for the determination of trace

chloride ions in water.

chloride * * * precipitation enrichment spectrophotometry

method is a national standard method [7]

. The method uses

lead phosphate precipitation as carrier, and * * precipitates to enrich

trace chloride. After centrifugal separation,

iron nitrate /

perchloric acid solution is used to completely dissolve

precipitate, and mercury thiocyanate /

methanol solution is added for color development. Trace chloride is indirectly determined by spectrophotometer, and the determination range is.

Spectrophotometry can accurately determine micro

amount of chloride ion with high sensitivity and good reproducibility.

The method is simple and

fast. However, the reagents of lead phosphate,

sulfur

mercuric cyanate and methanol used in * * * precipitation enrichment spectrophotometry are toxic substances, which

affect the health of operators, and these reagents are used in a large amount, which will cause serious environmental pollution

if they are discharged directly without treatment.

2.3

turbidimetry

This turbidimetry is developed on the basis of colorimetry, and it is an analysis method based on measuring the intensity of transmitted light

after passing through suspension, and has been used in clinical

analysis,

food analysis,

environmental analysis and

industry.

Chen Zhenhua et al. [8]

studied the determination of Cl

by silver nitrate turbidity method under the surface active agent. The results showed that Tween-61

was used as the

stabilizer of AgCl

turbidity at 1.3 mol/L

Wang Airong et al. [9]

studied the direct determination of trace chloride ions in acidic copper plating solution with glycol

as solubilizing agent and silver nitrate as precipitating agent by silver chloride turbidimetry without separating copper sulfate

. The wavelength of determination is

441 nm, and the linear range is 1~2 g/mL. It is

Yu Lingyun, et al.: The determination method of chloride ion and its application research industry forum

The apparent molar absorption coefficient ε=113 ×

115 in the 31

studied the test conditions of

AgCl

turbidity method for the determination of chloride ion with nonionic microemulsion emulsifier OP/

n-butanol /

n-heptane /

water as medium

. The linear range of this method is

1.2~3.4 mg/L,

r =1.9997,

RSD <:

2.8%, and the recovery rate is 94%~114%. It can be used for the determination of trace

chloride ions in cement raw materials,

raw materials and clinker.

Shen Haiyan [11]

Based on the stability of silver chloride precipitation in

gelatin -

ethanol aqueous solution,

a turbidimetric method for the determination of

trace chloride ions in organic process water was established. The linearity of this method is in the range of 1~6 mg/L,

r =1.9993, and the yield of back

is 95.2%~111.3%. Wang Zhaoxi et al. [12]

set the parameters of the flow injection analyzer

the working wavelength is 451 nm, and the sampling frequency is

times /h, and established a

turbidimetric method for the determination of chloride ion content in water with reverse flow injection ratio

. The concentration of chloride ion has a good linear relationship with the absorbance of

in the range of 1.1×

-5

~ 11.1× 11

-4

mol/L

, the correlation coefficient

is 1.995, and the recovery rate is 95%

~. 2.49%。

this turbidimetric method is easy to operate, short in analysis time, less in reagents, low in operation cost, simple in detection means, and can be combined with other advanced technologies, such as flow injection, so it is easy to realize automation and programming, and has a very broad prospect. Because

this turbidity method has the above characteristics, it is widely used in analytical science.

2.4

ion chromatography

ion chromatography is a relatively new ion

separation technology. This method has been widely used in environmental monitoring, analysis of salt water, soil,

blood

liquid,

boiler water and

dairy products. Zhang xinshen et al. [13]

used a self-made

ion chromatograph to determine the content of

chloride ions in the waste liquor of pickling,

chrome tanning and

total sewage in leather production. The results show that the concentration of chlorine

ion has a good linear relationship in the range of 11

- 5

~11

- 3

mol/L

, the upper limit of measurement

is 11

- 2

mol/L, and the recovery rate is 98.6. Zhu Ziping [14]

The influence of organic components in emulsion on

determined components and the pollution to chromatographic column were eliminated by extraction

separation method, and the chloride ions in emulsion were detected by ion chromatography. The average recovery rate of standard

is 95%~115%, and the relative standard

standard deviation is better than 4.1%(n=21).

Lu keping

et al [15]

decomposed hydrogen peroxide by heating and refluxing under alkaline conditions, and determined trace chloride ions in it by ion chromatography. The detection limit of

chloride ion in hydrogen peroxide is 1.16 g/mL, and the linear

equation is C=1.155 ×11

- 5

A- 1.

12435.

the linear range is 1.11~15.1

g/mL, and the correlation coefficient between concentration and area is r

=1.9992.

Wang Yanli et al. [16]

used high-purity Cu

powder and

concentrated HNO 3

for redox reaction, and heated at

171

℃ to decompose Cu(NO 3

, and removed most of NO3

-. The recovery rate of Cl

is 87.5% ~ 93.7%

RSD (n

= 5) <: 11%。 Yan Liu et al. [17]

used ion color

spectrum double column series method to separate nitric acid samples, and used

ion chromatography conductivity detection method to determine trace chloride ions in nitric acid

filtrate. The concentration

of chloride ion is linear with the peak area of color

spectrum in the range of 1.11~1.31 mg/L

, and the linear correlation coefficient

is r =1.997. The recovery rate of chloride ion is

96.5%~99.1%, and the determination results are relative.

song xiaonian et al [18]

used preconcentration ion

chromatography (sample

was preconcentrated by a concentration column and then came in) to determine trace

amount of chloride ions in high-purity water. After linear regression of the analysis results, the equation was

H = 1.429C- 1.596, where

is chloride ion content, and the linear correlation coefficient is r =

1.9985. The standard curve has a good linear

relationship, which can monitor chloride ions in high-purity deionized water

- 9

mg/L

ion chromatography is simple and convenient, with high sensitivity

, rapid and accurate measurement, and does not need other chemical reagents. It can be applied to practical analysis quickly,

simply,

efficiently and safely, and

it is especially suitable for continuous measurement

determination of large quantities of reagents.

2.5

atomic absorption method

atomic absorption is a method for quantitative analysis based on the absorption of specific spectral lines by

atomic vapor of the measured substance.

gu yongzuo et al [19]

based on the precipitation reaction of Cl

with quantitative Ag

to AgCl

, an indirect atomic absorption method for the determination of Cl

in water was proposed. The concentration of Cl

is linear in the range of 1~51 g/mL

. Qian Chuhong et al. [21]

indirectly determined

trace chloride ion in ammonium adipate by atomic absorption

collection method. By adding ethanol

and atomization synergist, the solubility of AgCl

was reduced and the atomization efficiency was improved, thus

the determination sensitivity was improved. By using

AgNO 3 < The residual Ag

was determined to indirectly calculate the content of

chloride ion. The relative standard

deviation was 1.9%~4.8%, and the sensitivity (1%A)

was 1.122 mg/L.

Ye Xiaoping [21]

Using ethanol -

gelatin can

improve the stability of silver chloride precipitation, and

Industry Forum

No.15

AEO- 7

surfactant can also significantly improve the atomization efficiency of silver

. The content of silver ions was determined by graphite furnace atomic absorption spectrometry

, and then the content of chlorine ions in rare earth oxide minerals with a fixed valence of

was indirectly determined. The linear range was 21~111

g/L, the correlation coefficient was r = 1.9997,

RSD

=1.27%, and the recovery rate was 92.5.

yang Yan et al. [22]

studied the indirect determination of trace chloride ions in high-purity water of power plant by flame atomic absorption spectrometry. The method uses

AgCl

precipitation to determine the residual Ag

indirectly

extracted chloride ion content. The relative standard deviation of the method is 2.3%~8.6%, the recovery rate is

94% ~113%, and the sensitivity (1% A) is

1.129 mg/L. Yuan Zhili et al. [23]

studied that in

acidic environment, chloride ion and silver ion formed

precipitation, and after being dissolved by ammonia water, silver was determined by pyrogen

neutron absorption method, thus indirectly determining the content of

chloride ion. The linear range of chlorine

determined by this method is 1.1~31 g/mL, the correlation