Multianion analysis, applications of ion chromatography - Determination of Anions in Natural and Treated Waters - page 663

Buchholz et al. [61] have described a procedure for the determination of less than 1µg
L −1 of chloride, nitrite and sulphate in 2ml of rainwater sample using non-suppressed ion
chromatography. Detection limits are less than 0.1mg L −1 for chloride and nitrate and
0.25mg L −1 for sulphate. The method can accomplish the simultaneous analysis of
chloride, nitrate, nitrite and sulphate in less than 25min (see Fig. 12.30).
Apparatus
Model 110 A high performance liquid chromatograph (Beckman) equipped with a 2ml
constant volume sample loop and a 4.6×250mm Wescan 269-001 anion column with
guard column. Detection of anions from column eluent is by measurement of
conductivity change as eluent flows at 1.8ml min −1 through the conductivity cell of a
conductivity detector (Wescan Model 213 A). The chromatograms, including peak area
data for each anion, were obtained on a reporting integrator (Hewlett Packard 3390A).
The anion calibration standard was prepared to contain 1.49, 1.64, and 1.52mg L −1
chloride, nitrate and sulphate respectively. The eluent buffer consisted of 2m mol L −1
potassium hydrogen phthalate adjusted to pH 4.5 with potassium hydroxide. All
standards, buffers and other chemicals were certified A.C.S. grade (Fisher). The handling
of all samples, standards, and buffers was accomplished with rubber gloves to prevent
anion contamination due to contact with hands.