Chelation Value of Polyaminopolycarboxylic Acids and Their Salts: Copper PAN Method
AATCC 168-2018 pdf free.Chelation Value of Polyaminopolycarboxylic Acids and Their Salts: Copper PAN Method.
NOTE: These safety precautions are for infonnation purposes only. The precautions arc ancillary to thc testing proccdures and are not intended to be all inclusive. It is the user’s responsibility to use safc and proper techniques in handling materials in this test method. Manufacturcrs MUST be consulted for specific details such as material safety data sheets and othcr manufacturer’s recommendations. All ()SI-IA standards and rules must also be consulted and followed.
Good laboratory practices should be followed. Wear safety glasses in all laboratory areas.
All chemicals should be handled with carc
In preparing, dispensing and handling glacial acetic acid and sodium hydroxide use chemical goggles or face shield, impervious gloves and an impervious apron. (‘oncentrated acids and bases should be handled only in an adequately ventilated laboratory hood. CAUTION: Always add acid to water.
Cupnc nitrate 2.5 hydrate is corrosive to the cyc and skin and is harmful if inhaled. It is an oxidiiing material and may react with organic materials. It should be handled only in an adequately ventilated hood.
Methanol is harmful if inhaled or swallowed and is a flammable liquid. It should be %tored in the laboratory only in small containers away from heat, open flames and sparks. This chemical should not be used near an open flame and should be handled only in an adequately ventilated hood.
An cycwashisafciy shower should be located nearby and a self-contained breathing apparatus should he readily available for emergency use.
Exposure to chemicals used in this procedure must be controlled at or below levels set by governmental authorities (e.g.. Occupational Safety and llealth Administration’s [OSHAJ permissible exposure limits [PEL) as found in 29 (‘FR 1910.10(X); see www.osha.gov for latest version). In addition, the American Conference of (iovemmental Industrial Hygicnis ts (ACGIH) Threshold limit Values (TLVs) comprised of time weighted averages (TLV-TWA), short term exposure limits (TLV-STEL.) and ceiling limits (TLV-C) are recommended as a general guide for air contaminant exposure which should be mc( (scc 14.1).
Reagents Acetic acid, I.ON(CH1COOH) Cupric nitrate 2.5 hydrate (Cu(N0). 2.511,0)
Ethylene diami nctetraacctic acid (free acid) (EDTA)(C1,,H)N,)
Methanol 1-4 2-Pyridylaio)-2-naphthol. (PAN) (CMHIIONI)
Sodium acetate trihydrate (CIIC(X)Na 311.0)
Sodium hydroxide. LON(NaOll)
Sampling Conduct the test in triplicatc; i.e., analyze 3 test specimens from a sample.
SpecImens
Do flOL use aluminum or metallic weighing pans.
For analysis of solid EDTA, HEDTA, and DTPA (either free acid or salt forms) weigh a 0.24-0.26 g specimen of the dried chelating agent to an accuracy of 0.01 g.
For analysis of commercial solution, of saks of the chelating agents, weigh aO.49-O.5l g spccimcn of the soluLion to an accuracy of 0.01 g.
Conditioning
If solid chelating agent is being evaluated, dry a 2-g sample at the appropriate temperature for at least 2 h and cool in a desiccator before weighing specimens.
Cupric Nitrate Solution: Dissolve 23.30 g of cupric nitrate 2.5 hydrate and dilute to 1.000 L in a volumetric flask.
Calculate the molarity of the cupric nitrate solution (see 11.1).
PAN Indicator: Dissolve 0.025 g of 1-(2-pyridylazo)-2-naphthol in 50 mL of methanol. Store in a refrigerator in a stoppered bottled. Prepare fresh weekly.
Acetate Buffer Solution: (pH 4.65). Dissolve 34.0 g of sodium acetate trihydrate in 500 mL of water and add 15 mL of glacial acetic acid. Mix well and store in a closed container.AATCC 168 pdf download.Chelation Value of Polyaminopolycarboxylic Acids and Their Salts: Copper PAN Method