Hugh Y. Yee

Abstract An AutoAnalyzer method has been developed in which the recently introduced reagent for iron, 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine ("ferrozine"), is used. With the Technicon colorimeter or Gilford 300-N spectrophotometer in use, sampling rates may be 30/h or 50/h, respectively. Sample volume is 0.8 ml, and measurements are made at 560 nm. A procedure for measuring total iron-binding capacity is also described.

Abstract Copper and iron may be sequentially measured in a single aliquot of a protein-free filtrate by use of bis (1 -piperidylthiocarbonyl) disulfide and disodium 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine (also known as ferrozine). Recovery studies showed excellent results for both metals in various concentrations. Copper interference has been obviated by use of thiourea in mercaptoacetic acid. Simultaneous equations are not needed in calculating results and high-reading blanks are eliminated. Comparative results are given with methods in which each metal was measured singly.

A revised procedure for processing a capillary blood sample collected on filter paper (FP) for analysis by graphite furnace atomic absorption spectrometry (GFAAS) is described. A 1/4-in. diameter disk of the dried FP sample was used, and a correlation of 0.975 with a false-positive rate of 0.8% and a false-negative rate of 1.7% was found when the results from the FP sample and its corresponding venous sample were compared. Several analytical variables were investigated, and the following was found: blood samples with hematocrit values of 30-39% did not show any significant differences between the paired FP and venous lead results; filter paper blank values were < 2 micrograms/dl with the use of aqueous standards without correction and 0.1 microgram/dl with paper blank correction; and during the collection of 163 samples from 6 different urban sites over a period of 1 year, no environmental lead contamination was encountered based upon the good agreement between all of the paired FP and venous lead results. The method described is easier to perform than an earlier version. All indications suggest that a fingerstick capillary blood sample collected on filter paper is suitable for lead screening. Proper precautions must always be taken to guard against contamination.

Abstract A simplified procedure utilizing ferrous ammonium sulfate-thiourea as the reductant for the determination of inorganic phosphate in serum and urine by the AutoAnalyzer is described. Elimination of the heating bath usually required for many phosphorus methods for color development yields an improved S.D. of ± 0.25 and facilitates troubleshooting during any apparatus malfunction. Comparison of results between the proposed method and that of Fiske and SubbaRow (1) is presented. Recoveries of added phosphorous in serum or urine are quantitative.