Determination of Small Quantities of Fluoride in Water, A Modified Zirconium-Alizarin Method

Guide for Preparation of Journal Manuscripts

“…The complete references should never be written into the text or included as footnotes. Reference data should include: for periodicals (1,5,6,7)-author's name complete, title of article, name of publication, volume number, issue number (if paged within the issue (7», page number, and year of publication; for books (2,3,4)author's name complete, title of book, publisher's name and address, edition, and year of publication. The following is a sample reference list:…”

Methods of Determining Fluorides

“…On this basis it will be noted that only five samples have a precision of less than 10 parts per hundred, or 10 per cent. Of these five samples, No, 13…”

“…dissolved solids places it second only to Sample 12 in this respect, yet the precision of its results is only slightly less than the mean of the 20 best samples. While only two of its 43 values fall exactly on the mean, 35, or 81 per cent, fall within 10 per cent of the mean; and of the 43 values, the highest number obtained in any sample, none had to be rejected.Sample13 may be compared at this point with Samples 19 and 21, slightly lower and higher respectively in fluorine content. Both of the latter samples are relatively low in dissolved solids, less than 300 p.p.m.…”

“…NOTE: Lamar and Seegmiller(13) have recently reported that quantities of fluoride less than about 0.4 p.p.m., which are difficult to determine by the usual methods, may be determined easily and accurately by using sulfuric acid instead of a mixture of sulfuric and hydrochloric acids or hydrochloric acid alone. It is essential that the pH be controlled accurately to obtain the maximum sensitivity.…”