Reagent Chemicals - ACS Specifications

Reagent Chemicals—ACS Specifications, 9th ed., American Chemical Society, Washington, DC, Sept. 1999. 

Examples of typical packaging labels from reagent grade chemicals. Label (a) provides the actual lot assay for the reagent as determined by the manufacturer. Note that potassium has been flagged with an asterisk ( ) because its assay exceeds the maximum limit established by the American Chemical Society (ACS). Label (b) does not provide assayed values, but indicates that the reagent meets the specifications of the ACS for the listed impurities. An assay for the reagent also is provided. 

The AGS Book. The ACS book, Feagent Chemicals—zA.CS Specifications, estabhshes a standard of quahty for reagents to be used in precise analytical work, for which purpose it contains both specifications and testing methods for some 350 reagent chemicals. 

Typical specifications for bromine produced ia a modem plant (54) generally exceed the ACS requirements for bromine used as a reagent chemical (55) (Table 4). 

Reagent grade chemicals, such as conforming to the ACS Specifications shall be used and water conforming to the Specifications for Reagent Water, ASTM Desigoation D1193... 

AMERICAN CHEMICAL SOCIETY, COMMITIEE ON ANALYTICAL REAGENTS Reagent Chemicals, American Chemical Society Specifications, 1960. ACS, Washington, D.C., 1961. 

ACS (American Chemical Society specifications) reagent (analytical reagent quality)... 

Reagent-grade chemicals conform to the minimum standards set forth by the Reagent Chemical Committee of the American Chemical Society (ACS) and are used wherever possible in analytical work. Some suppliers label their products with the maximum limits of impurity allowed by the ACS specifications others print actual concentrations for the various impurities. 

The American Chemical Society publishes a compendium of tests for evaluating the purity and quality of basic laboratory chemicals. Reagent chemicals that do not reference the ACS meet the manufacturer s own reagent specifications, which vary among suppliers. 

ACS Committee on Analytical Reagents (2006). Colorimetry and turbidimetry. Reagent chemicals Specifications and procedures 0 edn, (pp. 32-41). Oxford American Chemical Society-Oxford University Press. 

Standards for food-grade chemicals in the United States are set by the Committee on Eood Chemicals Codex of the National Academy of Sciences (NAS) which pubHshes them in the Food Chemicals Codex (ECC) (6) (see also Eood additives). Standards for laboratory reagents are set by the American Chemical Society (ACS) Committee on Analytical Reagents and are pubHshed in Feagent Chemicals—A.CS Specifications (7). Standards for electronic-grade chemicals, which have extremely low limits for trace ions, are pubHshed aimually in The Book of SEMI Standards (BOSS) by Semiconductor Equipment and Materials International (SEMI) (8). 

The 30% reagent-grade hydrogen peroxide is purer than the industrial grades, is covered by ACS reagent specification, and is used as a laboratory reagent and in some specialty uses (see Fine chemicals). Several grades are also marketed for electronics use and thus have exceptionally low impurity levels. Some of these latter contain very Httie or no stabilizers (see Electronic materials). 

Specifications and Standards, Shipping. Commercial iodine has a minimum purity of 99.8%. The Committee of Analytical reagents of the American Chemical Society (67) and the U.S. Pharmacopoeia XXII (68) specify an iodine content not less than 99.8%, a maximum nonvolatile residue of 0.01%, and chlorine—bromine (expressed as chlorine) of 0.005% (ACS) and 0.028% (USP), respectively. In the past these requirements were attained basicaHy only by sublimation, but with processing changes these specifications can be met by direct production of iodine. Previously the impurities of the Chilean product were chiefly water, sulfuric acid, and insoluble materials. Improvements in the production process, and especiaHy in the refining step, aHow the direct obtainment of ACS-type iodine. Also, because of its origin and production process, the Chilean iodine has a chlorine—bromine impurity level of no more than 0.002%. 

ACS certified A reagent that meets or exceeds the specifications of purity put forth by the American Chemical Society. The certificate of analysis is on the label. 

Table I gives a summary of the experimental conditions chosen for both types of experiments. In the growth rate experiments the reagent inflow rate (0-0.6 mol/h), temperature (70-95°C) and specific power input of stirring (0.02-1.29 W/kg) were varied. For the phase transformation experiments temperature (40-90°C) and solution composition (see Table II) was varied. All solutions and the solid material used in these experiments were prepared from ACS reagent grade chemicals.

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