Page:NIOSH Manual of Analytical Methods - 8308.pdf/1

 FLUORIDE in urine 8308

F-

METHOD: 8308, Issue 2 EVALUATION: FULL Issue 1: 15 February 1984 Issue 2: 15 August 1994

exposure to inorganic fluorides [1,2].

SYNONYMS: none.

urine, pre-and post-shift

50 mL in chemically clean polyethylene bottles

0.2 g EDTA added to bottles before collection

in insulated containers using bagged refrigerant

2 weeks @ 4 C, longer if frozen

collect 3 sets of specimens from unexposed workers (pre- and post-shift)

ION SELECTIVE ELECTRODE (ISE)

fluoride ion (F -)

mix equal volumes of urine with TISAB

solutions of sodium fluoride in water

spiked urine pools; correct for creatinine content

1 to 100 mg/L urine

0.1 mg/L urine

0.95 [3]

0.04

± 23.6%

Any fluorine-containing substances that can be metabolized to fluoride (F ) can be monitored using this procedure. Inorganic compounds of fluoride can be absorbed by the body resulting in the excretion of fluoride ions as sodium fluoride. Dietary and domestic water sources of fluoride must be considered, as well as dental treatments.

Hydroxide, the only positive interference, is eliminated by use of the buffer. Negative interferences from complexation of fluoride by cations, such as calcium, are minimized by EDTA preservative and the high ionic strength buf fer.

This method is P&CAM 114 [4] in a revised format. Other methods that have been used are those described in the NIOSH criteria documents on inorganic fluorides [1] and hydrogen fluoride [2].