1462/992 _HI 4010

Description

DESCRIPTION

The HI4010 is a solid state, half-cell ion selective electrode (ISE) for the determination of fluoride (F-) in solution. The lanthanum fluoride crystal membrane produces a potential change due to the fluoride ion exchange between the membrane and the sample. The internal sensing elements are housed within a durable epoxy body. The HI4010 is ideal for a variety of applications in drinking water treatment, environmental monitoring, and plating baths.

Solid state sensor
Detection from 0.02 mg/L to saturated F-
For use with HI5315 reference half-cell

Hanna’s solid-state half-cell ISEs are designed for use with the HI5315 reference half-cell. The reference half-cell features a cone style junction. The skirted cone geometry of the reference forms the liquid junction with the test solution at the tip of the junction cone, producing a highly stable reference potential and consistent flow rates of electrolyte into the solution. A simple press of the top portion of the ISE makes it easy to empty the electrolyte fill solution and replace when necessary.

For the HI4010 to accurately measure total fluoride concentration, it is important that the pH and ionic strength of the standards and sample be adjusted to a constant value. The total ionic strength adjustment buffer (TISAB) ensures that the solution pH is between pH 5 and 8 and that the activity coefficient is constant. The TISAB solution also preferentially complexes with various metal ions, such as aluminum and iron, which tend to form complexes with fluoride ions. TISAB thus ensures that these metal ions do not interfere, permitting an accurate total fluoride measurement. Measuring all solutions with a constant pH and ionic strength reduces the margin of error between measurements. The HI4010 fluoride solid-state ISE can measure from 1µM (0.02 mg/L) to saturated F^–.

Conversion Table for F^–

	Multiply
moles/L (M) to ppm (mg/L)	1.900 x 10⁴
ppm (mg/L) to M (moles/L)	5.263 x 10^-5

Features at-a-glance

Fixed Sensing Modules

Solid-state half-cell ISEs are electrodes that detect free ions in a solution. The lanthanum fluoride crystal sensing membrane is attached to the HI4010 fluoride half-cell by a fixed sensing module for ease of use.

Durable Epoxy Body

The probe body of the fluoride half-cell is composed of durable epoxy resin.

BNC Connection

The HI4010 has a universal BNC connector for easy connection to any benchtop meter with a female BNC probe input.

Theory of Operation

A solid-state sensor electrode develops a voltage due to the ion exchange that occurs between the solution and the inorganic membrane. An equilibrium occurs due to the highly limited solubility of the membrane material in the sample. When the ionic strength of the solution is fixed by the addition of ionic strength adjuster, the voltage is proportional to the concentration of free ions in solution.