To enhance flame retardation, polystyrene is brominated to achieve a final composition containing 25-35 % bromine. Determining the bromine content through combustion ion chromatography (CIC) requires a specially optimized absorption solution to effectively trap all bromide.
Image Credit: Metrohm Middle East FZC
This study demonstrates the optimization of an absorption solution tailored for high-bromine samples.
Results
Source: Metrohm Middle East FZC
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| 1 Bromine |
NaOH [0 mol/L] |
NaOH [10 mol/L] |
NaOH [20 mol/L] |
NaOH [30 mol/L] |
| Change in NaOH (400 mg/L H2O2) |
241.0 g/kg RSD = 4.9 %
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287.6 g/kg RSD = 3.6 % |
287.6 g/kg RSD = 1.5 % |
283.8 g/kg RSD = 1.8 % |
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H2O2 [100 mg/L] |
H2O2 [200 mg/L] |
H2O2 [400 mg/L] |
H2O2 [800 mg/L] |
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Change in H2O2 (20 mmol/L NaOH)
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288.2 g/kg RSD = 2.8 %
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270.6 g/kg RSD = 2.0 %
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281.5 g/kg RSD = 1.8 %
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284.8 g/kg RSD = 2.9 %
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Sample Preparation
The brominated polystyrene sample was analyzed using a Combustion IC with flame sensor technology and an intelligent Partial Loop Injection Technique with Inline Matrix Elimination.
Columns
Source: Metrohm Middle East FZC
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| Metrosep A Supp 16 - 100/4.0 |
6.1031.410 |
| Metrosep A Supp 4/5 Guard/4.0 |
6.1031.500 |
| Metrosep A PCC 1 HC/4.0 |
6.1006.310 |
| Metrosep A Trap 1 - 100/4.0 |
6.1014.000 |
| Metrosep I Trap 1 - 100/4.0 |
6.1014.2 |
Solutions
Source: Metrohm Middle East FZC
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| 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 - 800 mg/L hydrogen peroxide 0 - 30 mmol/L sodium hydroxide |
Parameters
Source: Metrohm Middle East FZC
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| Flow rate |
0.7 mL/min |
| Injection volume (IC) |
10 μL (MiPT) |
| Pmax |
15 MPa |
| Recording time |
14 min |
| Column temperature |
45 °C |
Combustion Parameters
Source: Metrohm Middle East FZC
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| Argon |
100 mL/min |
| Oxygen |
300 mL/min |
| Oven temperature |
1050 °C |
| Post-combustion time |
600 s |
| Initial volume of absorption solution |
4.0 mL |
| Water inlet |
0.2 mL/min |
Analysis
Source: Metrohm Middle East FZC
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| Conductivity after sequential suppression |
Instrumentation
Source: Metrohm Middle East FZC
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| 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)
This information has been sourced, reviewed and adapted from materials provided by Metrohm Middle East FZC.
For more information on this source, please visit Metrohm Middle East FZC.