Halobutyl rubber is widely used in the manufacture of pharmaceutical stoppers. This material is ideally suited for this application as it has chemical resistance and exhibits low permeability to gases.
This Application Note describes the analysis of halogen and sulfur content of chlorinated and brominated butyl rubber stoppers. Hydropyrolysis of the sample results in the release of halogen and sulfur compounds, which are subsequently analyzed using ion chromatography (IC).
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Sample
Halogenated butyl rubber
Sample preparation
In this work, the sample analysis is performed by Combustion IC with flame sensor technology and intelligent partial loop injection technique with inline matrix elimination.
Columns
|
Metrosep A Supp 16 - 150/4.0
|
6.1031.420
|
|
Metrosep A Supp 16 Guard/4.0
|
6.1031.500
|
|
Metrosep A PCC 1 HC/4.0
|
6.1006.310
|
Solutions
|
Eluent
|
7.5 mmol/L sodium carbonate 0.75 mmol/L sodium hydroxide
|
|
Suppressor regenerant
|
250 mmol/L sulfuric acid
|
|
Rinsing solution
|
STREAM
|
|
Absorber solution
|
100 mg/L hydrogen peroxide
|
Parameters
|
Flow rate
|
0.8 mL/minutes
|
|
Injection volume (IC)
|
20 μL (MiPT)
|
|
Pmax
|
20 MPa
|
|
Recording time
|
18 minutes
|
|
Column temperature
|
45 °C
|
Combustion parameters
|
Argon
|
100 mL/minutes
|
|
Oxygen
|
300 mL/minutes
|
|
Oven temperature
|
1100 °C
|
|
Post-combustion time
|
500 s
|
|
Initial volume of absorption solution
|
4.0 mL
|
|
Water inlet
|
0.2 mL/minutes
|
Analysis
Conductivity after the sequential suppression
Instrumentation
|
930 Compact IC Flex Oven/SeS/PP/Deg
|
2.930.2560*
|
|
IC Conductivity Detector
|
2.850.9010*
|
|
MSM Rotor A
|
6.2832.000*
|
|
Adapter sleeve for Suppressor Vario
|
6.2842.020*
|
|
920 Absorber Module
|
2.920.0010*
|
|
Combustion Module (oven and ABD)
|
2.136.0700*
|
|
Autosampler MMS 5000
|
2.136.0800
|
|
Kit for solid sampling
|
6.7302.000
|
* Available as 930 Metrohm Combustion IC (2.930.9010)
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Results
.png)
|
|
Chlorinated butyl rubber
|
Brominated butyl rubber*)
|
|
Conc. [mg/kg]
|
RSD [%]
|
Conc. [mg/kg]
|
RSD [%]
|
|
1
|
Fluorine
|
36
|
1.2
|
< 100
|
|
|
2
|
Chlorine
|
6582
|
2.6
|
290
|
23
|
|
3
|
Bromine
|
n.d
|
-
|
8595
|
1.9
|
|
4
|
Sulfur
|
62
|
2.9
|
2509
|
3.
|
*) Chromatogram shown above
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This information has been sourced, reviewed and adapted from materials provided by Metrohm AG.
For more information on this source, please visit Metrohm AG.