Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Precipitation Titration: Endpoint Detection Methods

Precipitation Titration: Endpoint Detection Methods

In argentometric precipitation titrations, endpoints can be detected visually by the Mohr, Volhard, and Fajans methods. In the Mohr method, adding a soluble chromate indicator gives an initial yellow color to the analyte solution. As the titrant is added, the first excess of silver ions forms a red silver chromate precipitate, marking the endpoint. The solution pH should be maintained at about 8 by adding solid CaCO3.
In the Volhard method, a standard excess of AgNO3 is first added to the...

Qualitative Analysis

Qualitative Analysis

For solutions containing mixtures of different cations, the identity of each cation can be determined by qualitative analysis. This technique involves a series of selective precipitations with different chemical reagents, each reaction producing a characteristic precipitate for a specific group of cations. Metal ions within a group are further separated by varying the pH, heating the mixture to redissolve a precipitate, or adding other reagents to form complex ions.
For instance, group IV...

Precipitation and Co-precipitation

Precipitation and Co-precipitation

Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...

Washing, Drying, and Ignition of Precipitates

Washing, Drying, and Ignition of Precipitates

After filtration, the precipitate is washed to remove coprecipitated impurities and any remaining mother liquor. Colloidal precipitates, such as silver chloride, are washed with an electrolyte (such as dilute nitric acid) to prevent the peptization of the precipitate. In the case of slightly soluble precipitates, the wash solution contains a common ion to reduce solubility. Lead sulfate, which is slightly soluble in water, is washed with dilute sulfuric acid. Similarly, wash solutions may be...

Gravimetry: Inorganic And Organic Precipitating Agents

Gravimetry: Inorganic And Organic Precipitating Agents

In gravimetry, the precipitant is chosen carefully to obtain a pure solid that can be easily filtered. Common inorganic precipitants can be used to determine several cations and anions. In some cases, the formation of the same precipitate can be used to determine the cation and the anion. For example, the reaction of barium and chromate ions to give barium chromate is used to determine both barium and chromate. However, precipitates such as hydroxides, oxalates, and metal ammonium phosphates...

Precipitation Gravimetry

Precipitation Gravimetry

Precipitation gravimetry is based on converting an analyte into a sparingly soluble precipitate, which is separated by filtration and weighed. An ideal precipitate should be pure, insoluble, of known composition, and easily filtered from the reaction mixture.
In determining nickel by gravimetric analysis, a precipitant of ethanolic dimethylglyoxime is added to a hot nickel salt solution. This is quickly followed by the dropwise addition of dilute ammonia solution until precipitation occurs. A...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

Continuous Hydrogen Sulfide Monitor Based on Positive Fluorescence Green Chemistry. Application to Geothermal Powerplant Environmental Impact Assessment.

ACS omega·2026

Same author

Low flow liquid flowmetry. A tutorial review.

Talanta·2026

Same author

Functionalization of High-Density Polyethylene Capillaries for Open Tubular Ion Chromatography.

Journal of separation science·2024

Same author

Forbidden ion transport through cation exchange membranes.

Talanta·2024

Same author

Liquid phase detection in the miniature scale. Microfluidic and capillary scale measurement and separation systems. A tutorial review.

Analytica chimica acta·2024

Same author

The Air Quality Index (AQI) in historical and analytical perspective a tutorial review.

Talanta·2023

Search research articles

Related Experiment Video

Updated: Jul 12, 2026

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Published on: July 1, 2016

Sample processing method for the determination of perchlorate in milk.

Jason V Dyke¹, Andrea B Kirk, P Kalyani Martinelango

¹Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79401-1061, United States.

Analytica Chimica Acta

|August 29, 2007

Summary

A new, reagent-free method simplifies perchlorate determination in milk. This technique efficiently prepares samples for analysis, crucial for infant health assessments.

More Related Videos

Electrochemical Preparation of Poly(3,4-Ethylenedioxythiophene) Layers on Gold Microelectrodes for Uric Acid-Sensing Applications

Electrochemical Preparation of Poly(3,4-Ethylenedioxythiophene) Layers on Gold Microelectrodes for Uric Acid-Sensing Applications

Published on: July 28, 2021

Detecting the Water-soluble Chloride Distribution of Cement Paste in a High-precision Way

Detecting the Water-soluble Chloride Distribution of Cement Paste in a High-precision Way

Published on: November 21, 2017

Related Experiment Videos

Last Updated: Jul 12, 2026

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Published on: July 1, 2016

Electrochemical Preparation of Poly(3,4-Ethylenedioxythiophene) Layers on Gold Microelectrodes for Uric Acid-Sensing Applications

Electrochemical Preparation of Poly(3,4-Ethylenedioxythiophene) Layers on Gold Microelectrodes for Uric Acid-Sensing Applications

Published on: July 28, 2021

Detecting the Water-soluble Chloride Distribution of Cement Paste in a High-precision Way

Detecting the Water-soluble Chloride Distribution of Cement Paste in a High-precision Way

Published on: November 21, 2017

Area of Science:

Environmental Chemistry
Analytical Chemistry
Food Safety

Background:

Perchlorate contamination is increasingly found in various food and water sources.
Significant perchlorate levels detected in both human and dairy milk pose health risks, especially for infants and children.
Traditional milk sample preparation for perchlorate analysis is time-consuming and requires chemical additives, compromising trace analysis.

Purpose of the Study:

To develop an efficient, reagent-free sample preparation method for perchlorate determination in milk.
To overcome limitations of existing milk processing techniques, such as chemical additions and lengthy procedures.
To ensure accurate and reliable perchlorate analysis in milk for health impact assessments.

Main Methods:

Developed a reagent-free method involving sample spiking with isotopically labeled perchlorate.
Utilized centrifugation to remove lipids from milk samples.
Employed a 10 kDa molecular weight cutoff centrifugal ultrafilter for further sample cleanup.
Analyzed processed samples using ion chromatography-mass spectrometry (IC-MS).

Main Results:

Successfully processed both bovine and human milk samples, yielding 5-10 ml of clear liquid from 20 ml samples.
Achieved good recoveries through standard addition experiments.
Demonstrated high repeatability, with a range of 3-6% R.S.D. for multiple sample cleanup runs.
Validated the method's applicability for determining iodide and thiocyanate in milk as well.

Conclusions:

The developed reagent-free ultrafiltration method is effective for preparing milk samples for perchlorate analysis.
This technique significantly simplifies sample preparation, reduces analysis time, and avoids undesirable chemical reagents.
The method is robust, repeatable, and suitable for routine analysis of perchlorate and other contaminants in milk, supporting public health monitoring.