01 Solution Summary
BTEX compounds such as benzene, toluene, ethylbenzene, and xylene in indoor air sampling samples are collected and enriched by sorbent tubes and then introduced into GC or GC-MS after thermal desorption and focusing transfer. Quantification and quality control use the following arrangements: identification is performed based on the retention behavior of target components and reference standards; calibration is performed with reference standards corresponding to BTEX compounds such as benzene, toluene, ethylbenzene, and xylene, using external standard or internal standard calibration according to the applicable method; injection blanks, calibration checks, and parallel determinations are used to monitor contamination and response stability. The analytical batch is also set up with blanks, calibration checks, and applicable quality control samples.
02 Standards and Method Basis
Method basis: application method. The laboratory may enter the name and version of the adopted formal method into the project file.
03 Samples and Analytes
The specific samples areIndoor air sampling samples, and the analytes areBTEX compounds such as benzene, toluene, ethylbenzene, and xylene. Pretreatment, injection, and detection configurations are determined according to the sample state, target concentration, and the formal method adopted.
04 Method Principle
When air or exhaust gas passes through the sorbent tube, target VOCs are enriched by the sorbent material. The thermal desorption device heats the sorbent tube to release target compounds and sends them into the chromatographic system through a focusing and transfer flow path.
05 Sample Collection and Pretreatment
Before use, sorbent tubes are blank-checked and labeled; after sampling, both ends are sealed, and they are transported and stored according to the applicable method. Thermal desorption batches include unsampled tube blanks and applicable spiked tubes.
06 Separation and Detection
Desorbed components enter the GC system, where they are separated, and responses are acquired by FID. The transfer path is kept inert and cold spots are reduced.
07 Instrument System Configuration
| Module | Configuration | Role in This Solution |
|---|---|---|
| Sampling | Sorbent tubes and sampling pumps | Enrich target VOCs |
| Thermal desorption and injection | Thermal desorption transfer injection | Release, focus, and transfer target analytes |
| Chromatographic system | GC | Complete separation of components |
| Detection Unit | FID | Acquire target analyte responses |
08 Huishi Instruments Compatible Products
GC-460 gas chromatograph
- Product name
- GC-460 gas chromatograph
- Model
- GC-460
- Brand
- Huishi Instruments
- Manufacturer
- Shanghai Huishi Instrument Equipment Co., Ltd.
- Product category
- Gas chromatograph
- Role of the solution
- It undertakes the tasks of sample injection, separation, detection, and data acquisition in GC analysis.
- Reason for suitability
- The GC-460 can be configured with an FID and thermal desorption transfer injection, and is used for the separation and detection of benzene, toluene, ethylbenzene, xylene, and other benzene series compounds in indoor air sampling samples.
09 Analysis workflow
10 Qualitative, Quantitative, and Quality Control
Identification is performed based on the retention behavior of target components and reference standards; calibration is performed using reference standards corresponding to benzene, toluene, ethylbenzene, xylene, and other benzene series compounds by external standard or internal standard according to the applicable method; injection blanks, calibration checks, and parallel determinations are used to monitor contamination and response stability. Sorbent tube blanks, transport blanks, spiked tubes, and calibration checks are used to monitor background and recovery.
11 Method and Configuration Selection
- The sorbent material is matched to the target VOC range.
- The desorption, focusing, and transfer flow path serves as a continuous sample introduction chain.
12 Frequently Asked Questions
Why is thermal desorption-GC used for benzene, toluene, ethylbenzene, xylene, and other benzene series compounds?
Thermal desorption-GC matches the physicochemical properties, sample inlet, and detection objectives of benzene, toluene, ethylbenzene, xylene, and other benzene series compounds; the complete route simultaneously covers the processing, separation, detection, and data quality control of indoor air sampling samples.
What samples is this solution applicable to?
The applicable samples are indoor air sampling samples. When the sample source or matrix changes, the impact of coexisting components on pretreatment, separation, and detection response should be re-evaluated.
What components or indicators are included in the detection targets?
The analytes are benzene, toluene, ethylbenzene, xylene, and other benzene series compounds; both the main text and configuration are bounded by this entity scope.
How is quality controlled for an analytical batch?
For each batch of samples, set up method blanks, calibration verification, duplicate samples, or applicable QC samples, and retain records of sample processing, instrument conditions, calibration, and calculations.
What information is required before configuration?
It is recommended to provide real samples, a list of target compounds, expected concentration ranges, testing batch size, the method to be followed, and existing equipment conditions.
How are results kept traceable?
Sample numbers, reference materials, processing batches, instrument methods, raw data, calibration results, and review records together form the result traceability chain.
Why does thermal desorption use sorbent tubes?
Sorbent tubes can enrich VOCs from air during the sampling stage and then release them into the chromatographic system through controlled heating.
13 Related Solutions and Knowledge
Get Configuration and Technical Consultation
Please provide sample information for indoor air sampling samples, the concentration ranges of benzene homologues such as benzene, toluene, ethylbenzene, and xylene, the testing batch size, the method basis, and the existing equipment. Huishi Instruments will compile a configuration list based on this.
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