FLUORIDE in urine
F-
MW: 19.00
METHOD: 8308, Issue 2
8308
CAS: 16984-48-8
RTECS: LM6290000
EVALUATION: FULL
BIOLOGICAL INDICATOR OF:
Issue 1: 15 February 1984 Issue 2: 15 August 1994
exposure to inorganic fluorides [1,2].
SYNONYMS: none.
SAMPLING
MEASUREMENT
SPECIMEN:
urine, pre- and post-shift
TECHNIQUE:
ION SELECTIVE ELECTRODE (ISE)
VOLUME:
50 mL in chemically clean polyethylene bottles
ANALYTE:
fluoride ion (F )
DILUTION:
mix equal volumes of urine with TISAB
PRESERVATIVE: 0.2 g EDTA added to bottles before collection SHIPMENT:
SAMPLE STABILITY: CONTROLS:
CALIBRATION:
solutions of sodium fluoride in water
in insulated containers using bagged refrigerant
QUALITY CONTROL:
spiked urine pools; creatinine content
2 weeks @ 4 C, longer if frozen
RANGE:
1 to 100 mg/L urine
collect 3 sets of specimens from unexposed workers (pre- and post-shift)
ESTIMATED LOD:
0.1 mg/L urine
RECOVERY:
0.95 [3]
PRECISION (Sr):
0.04
ACCURACY:
± 23.6%
correct
for
APPLICABILITY: 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 so dium fluoride. Dietary and domestic water sources of fluoride must be considered, as well as dental treatments.
INTERFERENCES: 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.
OTHER METHODS: 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].
NIOSH Manual of Analytical Methods (NMAM), Fourth Edition, 8/15/94
