This Standard sets out a method for the collection and separation of gaseous and particulate fluorides from ambient air and their determination using a fluoride ion-selective electrode. Other analytical methods may be used; however, they are outside the scope of this Standard.This method is applicable to the measurement of gaseous and acid-soluble particulate fluorides suspended in ambient air at concentrations of 0.020 µg/m3 and greater.For a 24 h sampling period at a flow rate of 0.83 L/s (approximately 50 L/min), an atmospheric concentration of 0.15 µg/m3 of hydrogen fluoride in air can be measured, with measurement uncertainty of 10%.The lower limit of detection can be improved by sampling for longer periods, to a maximum of seven days (0.020 µg/m3); however, the accumulated particulate matter may interfere with the collection of gaseous fluorides, especially if alumina is present in the particulate matter. The upper limits of detection for gaseous fluoride are 45 µg/m3 for a 24 h sampling period and 6.5 µg/m3 for a seven day sampling period (at which point partial neutralization of the alkali-impregnated final filter affects the results). The presence of acid gases other than hydrogen fluoride will also reduce the upper limit of detection.The resultant determination for a sampling period greater than two days may indicate elevated particulate fluoride levels with depleted gaseous fluoride levels but the total value will still be valid (see Clause 7.2).

Originated as AS 2616.2—1984.Previous edition AS 3580.13.2—1991.Jointly revised and designated as AS/NZS 3580.13.2:2013. Originated as AS 2616.2-1984. Previous edition AS 3580.13.2-1991. Jointly revised and designated as AS/NZS 3580.13.2:2013.