Metrohm viva 1.1 - Manual (Page 1066)

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viva 1.1
The previously measured intercept solution is exchanged for a (bath) sam-
ple spiked with suppressor and the latter is measured.
Standard addition
Brightener standard solution is added once or several times to the measur-
ing solution and a measured value is recorded each time. The concentra-
tion of brightener in the sample is then calculated by means of linear
regression.
Example
Leveler
A leveler is an electroplating bath additive that reduces metal plating and
smoothens the metal layer surface. Levelers are only used in three-compo-
nent galvanic baths (suppressor, brightener and leveler), which are pre-
dominantly applied in semiconductor production and only rarely in printed
circuit board production.
MLAT (Modified Linear Approximation Technique)
Calibration method based on a standard addition and mainly used for the
determination of brightener in electroplating baths. First, the basic solu-
tion spiked with suppressor, referred to as the intercept solution, is mea-
sured. After the addition of sample to the intercept solution, another mea-
surement is made. This is followed by a standard addition with brightener
standard solution.
Determination of the intercept value
The intercept solution, which consists of VMS (Virgin Makeup Solution)
and suppressor is measured first. The area of the oxidation peak obtained
from the anodic sweep is evaluated, and the charge is calculated and
saved as intercept value. This value is then subtracted as a background
value from the subsequent measured values.
Sample measurement