Supplementary Information for “Reagent Chemicals”, 5th Edition Hydrochloric Acid
The ACS Committee on Analytical Reagents wishes to announce additional modifications of requirements or tests prior to the publication of the first supplement. For other modifications refer to Vol. 47, No. 7 , p 1149.
On page 301, lines 2 and 3 under Standard Solution, delete the phrase “with water’’.
Acetic Acid, Glacial
Lead
On page 51 in the requirement for Acetic Anhydride, line 3, change the concentration of the 4,4’-methylenedianiline solution from 0.10% to 1.0% (the preparation of the solution is stated correctly).
On page 330, line 2, change 885 ml to 910 ml.
Methyl Red Indicator On page 40, change page 000 to page 405.
Ammonium Chloride
Starch, Soluble
Sample Solution A and Blank Solution B for the determination of Phosphate, Sulfate, Heavy Metals, and Iron. Revise the last sentence on page 75 as follows: “Dissolve the two residues in separate 5-ml portions of 1 N ace-
On page 618, change two of the requirements as cited below: pH of a 2% solution. From 5.0 to 7.0 a t 25 “C. Residue after ignition. Not more than 0.4%.
tic acid and 50 ml of water, filter if necessary, and dilute with water to 100 ml (1ml of Sample Solution A = 0.25 g).”
Calcium Carbonate, Chelometric Standard On page 164, under Requirements, add the following: Fluoride (F). Not more than 0.0015%.
CORRECTION Substituted Benzophenone as Fluorometric Reagent in Automated Determination of Nitrate
In this article by B. K. Afghan and d. F. Ryan, Anal. Chem., 47, 2347 (1975), there is an error in the tenth reagent listed in Table I. The reagent called 2,2’,4-trihydroxy-4-methoxybenzophenone should be 2,2’-dihydroxy-4methoxybenzophenone; similarly the formula should be
ADDENDUM
Sulfanilic Acid On page 627, in the test for Nitrite, substitute, if necessary, N-naphthylethylenediamine dihydrochloride for 1naphthylamine hydrochloride, which may be unavailable.
port some confirmational measurements that have since been completed. The effect of continued rinsing of the MnOz was studied and it was found that only one rinse was needed at low pH’s and none a t high pH’s to give reproducible results. At a pH of about 1.9, an average manganese concentration of 4 ppm was determined, after one rinse, and this remained constant for as many as six additional rinses. This compares to 1.3 ppm a t a pH of 2.1 reported previously by us. A t a pH of about 9.7,
