The composition of leather odor is complex, including alkanes, alkenes, aromatic hydrocarbons, and low boiling polycyclic aromatic hydrocarbons. Genuine leather undergoes processes such as tanning, dyeing, fatliquoring, and coating from the original leather to the finished product. The residual chemicals and volatile compounds produced by the leather itself cause a certain odor in the genuine leather of office furniture. The detection of genuine leather odor in office furniture is an important part of quality evaluation, and the problem of leather odor is quite common in the production of office furniture. Currently, most office furniture companies in China use subjective evaluation methods to detect genuine leather odor. This method relies on sensory judgment and is easily influenced by factors such as personnel, time, and environment, resulting in significant differences in results. To overcome the above problems, it is necessary to introduce more objective evaluation methods to provide data support and scientific basis.
This study uses electronic nose technology to qualitatively analyze the odor of genuine leather in office furniture, providing objective analysis data. At the same time, combined with the subjective evaluation of genuine leather odor by experimental personnel, the analysis mode combining biomimetic technology and subjective evaluation method is explored, aiming to provide reference for the judgment of genuine leather odor quality.
01
AIRSENSE electronic nose
AIRSENSE electronic nose is a precision instrument that integrates advanced technology, with its core being the simulation of the operating mechanism of the biological olfactory system. The instrument is equipped with a high-sensitivity array composed of multiple metal oxide (MOS) sensors inside. The scent of genuine leather releases specific volatile organic compounds, whose composition and content vary depending on the material. The electronic nose utilizes this feature by capturing these "odor signals" through its internal gas sensor array.

02
Core equipment and experimental design

01
Main instruments and details
Experimental instrument: German AIRSENSE electronic nose.
The AIRSENSE electronic nose was selected for the study, which is equipped with a high-sensitivity metal oxide sensor and can respond specifically to different types of volatile compounds (such as W1S detection of short chain alkanes, W2S recognition of alcohol aldehydes and ethers, W1W capture of inorganic sulfides). It has the advantages of fast response, multi gas recognition, and portability. The experiment takes office furniture genuine leather from three different sources and processes of raw materials as the object, and implements subjective odor method and electronic nose objective detection simultaneously. The specific plan is as follows:
02
Data processing strategy
Using WinMuster software for data analysis, combined with principal component analysis (PCA) to extract core features, visualizing odor fingerprint differences through radar images, and establishing a correlation model between sensor response and odor components.

03
Results and Discussion

Verification of the correlation between subjective and objective testing
Correspondence of odor levels: The response intensity of the electronic nose is positively correlated with subjective scores - Sample 3's wet subjective score is level 4 (exceeding the standard), and the sensor response values corresponding to alcohol aldehydes, ethers, and short chain alkanes are more than 40% higher than Sample 1 (subjective levels 1-3); The control group (empty cans) had a subjective level of 1, and the responses of all electronic nose sensors were close to baseline.

Quantitative presentation of environmental impact: Wet samples accelerate the release of volatile compounds due to moisture, and the number of response sensors detected by the electronic nose increases by 3-4 compared to dry samples. Among them, the W2S (alcohol aldehyde ether) sensor has the largest increase in response, confirming the sensory experience of "increased odor in humid environments".
Accurate positioning of odor components
The PCA analysis of sample 2 showed that the variance contribution rate of the first principal component was 87.06%, the second principal component was 8.86%, and the cumulative total reached 95.91%, indicating that the electronic nose can fully capture odor characteristics. Further analysis revealed that:
The odor mainly comes from alcohol aldehyde ether components (W2S sensor) and short chain alkanes such as methane (W1S sensor), with both contributing more than 90%;

Hydrogen gas (W6S), weakly polar alkanes (W5C) and other components have a weak impact on odor, and the possibility of using them as key detection indicators can be ruled out.
Preparation of standardized testing standards
Establish an electronic nose detection standard for sample 2 through 100 effective wet state experiments:
The radar chart shows a "droplet shaped" distribution, with the W5S (nitrogen oxide compound) sensor having the highest response value (mean 1.83), while the response values of other sensors are in the range of 0.77-1.37;
When the mean is exceeded by ± 20% or the contour of the radar image is abnormal, a secondary detection should be initiated. This standard increases the repeatability of the detection from 65% of the subjective method to 92%.

04
Reshaping the Quality Control System of Genuine Leather

Rapid screening at the production end: AIRSENSE electronic nose single detection only takes 5-10 minutes, which is more than 90% shorter than GC-MS, and can be integrated into the production line to achieve real-time monitoring of raw material entry and finished product exit, avoiding the flow of unqualified materials into subsequent processes.
Standardized technical support: The established odor fingerprint database can replace manual experience and provide a unified detection reference for the office furniture industry, solving the industry pain point of "differences in evaluation results among different institutions".
Early warning of health risks: Abnormal responses from aldehyde related sensors (such as sensor 8) can indirectly indicate the risk of harmful substances such as formaldehyde, which can help identify target components for subsequent GC-MS quantitative analysis and reduce detection costs.

05
Conclusion

At present, the AIRSENSE electronic nose has been combined with GC-MS to build an integrated system of "qualitative screening+quantitative verification". With its objective, fast, and portable characteristics, the AIRSENSE electronic nose breaks the traditional mode of relying on artificial senses for odor detection of office furniture genuine leather. By establishing an odor fingerprint and component correlation model, this technology not only achieves accurate differentiation of odor levels, but also provides quantitative data support for subjective evaluation. With the upgrading of sensor technology and algorithm optimization, electronic noses are expected to promote the establishment of refined odor detection standards in the office furniture industry that are on par with the automotive industry, and build the first line of defense for indoor healthy environments.