Problems in Hemodialysis

To the Editor: In their editorial in the January 21 issue, Drs. Friedman and Lundin¹ draw attention to the desirability of limiting exposure to formaldehyde to a minimum. They note that the Clinitest reaction fails to detect concentrations of formaldehyde below 50 parts per million. It is therefore important to point out that many dialysis units abandoned the use of Clinitest for this purpose years ago in favor of the Schiff reagent, which, when used in ratios of 1:1 to 3:1 with the test sample, detects formaldehyde at a concentration of 3.6 to 5 parts per million.² The reagent is. . No extract is available for articles shorter than 400 words.