Methods for biological monitoring: a manual for assessing human exposure to hazardous substances. Kneip TJ, Crable JV eds. Washington, DC: American Public Health Association, 1988 Dec; :229-235
A method for determining aluminum (7429905), barium (7440393), cadmium (7440439), chromium (7440473), copper (7440508), iron (7439896), lead (7439921), manganese (7439965), molybdenum (7439987), nickel (7440020), platinum (7440064), silver (7440224), strontium (7440246), tin (7440315), titanium (7440326), and zinc (7440666) in urine was described. A 50 milliliter (ml) sample was adjusted to pH 2.0 with 5 molar sodium-hydroxide. The samples were extracted twice with 60 milligram portions of polydithiocarbamate resin. After filtering, the combined filter and resin were ashed in a low temperature oxygen plasma asher for 6 hours or digested with a 4:1 mixture of concentrated nitric-acid and perchloric-acid. For samples that were ashed, 0.5ml of 4:1 concentrated nitric- acid/perchloric-acid was added after ashing and the samples were transferred to 5ml volumetric flasks and diluted to volume with distilled deionized water. Wet digested samples were heated to dryness and reconstituted in 2 to 3ml of a mixture of 4 percent nitric-acid and 1 percent perchloric-acid (dilution acid). They were transferred to a 10ml volumetric flask and diluted to the mark with dilution acid. The ashed or digested samples were then analyzed by inductively coupled argon plasma atomic emission spectrophotometry. The spectrometer was calibrated with an acid blank and an 10 micrograms/ml (microg/ml) multielement solution. The method could analyze analyte concentrations of 0.25 to 200microg for a 50ml sample (microg/50ml). The detection limit was recoveries ranged from 77 to 100 percent. The precision based on four replicate determinations of the spiked samples ranged from 0.040 to 0.50microg/50ml.