# Applications of Nanomaterial Coatings in Solid-Phase Microextraction (SPME)
## 3 Range of Compounds to Which SPME Has Been Applied
### Volatile Organic Compounds (VOCs)  
The non-invasive nature of volatile organic compound (VOC) analysis and its comparatively inexpensive sample and analysis costs make it a viable method for identifying putative cancer biomarkers and other applications. Since its introduction by [PERSON] in 1989, SPME has gained popularity as a method for extracting volatile organic compounds (VOCs) from both in vitro and in vivo samples. Because of its ease of use, lack of solvents, automation potential, and compatibility with both liquid and gas chromatography, SPME is widely used in many different industries [25].  
[PERSON] et al.'s study identified twelve compounds that distinguish rice from Korea and China by analyzing white rice from the two nations using DVB/CAR/PDMS-SPME with GC-MS. More research is needed on 10 new hydrocarbon determinants, while hexanal and 1-hexanol levels were related to storage and environmental conditions. They came to the conclusion that additional food products could benefit from this technique, which can differentiate white rice based on its origin [26].  
A study by [PERSON] et al. evaluated the potential of aldehydes, which are biomarkers of oxidative stress, as non-small-cell lung cancer (NSCLC) diagnostic tools. Linear aldehydes (C3-C9) in exhaled breath were quantified by the researchers using a solid-phase microextraction (SPME) technology with GC/MS analysis. With detection and quantification limits of \(1\times 10^{-12}\) M and \(3\times 10^{-12}\) M, respectively, the approach showed excellent linearity over a range of 3.3-333.3 \(\times\) 10\({}^{-12}\) M. Precision (as a percentage RSD) was between 7.2 and 15.1%, while accuracy was above 93%. At +4 \({}^{\circ}\)C, aldehyde stability in a Bio-VOC\({}^{\circledR}\) tube lasted 10-17 h, but with certain fiber storage, it lasted for more than 10 days. In a clinical study, breath samples from 40 NSCLC patients and 38 asymptomatic non-smokers revealed significantly higher aldehyde levels in the NSCLC group, with age and smoking having no effect. A 90% discrimination power based on aldehyde patterns was verified by multivariate analysis, indicating that these chemicals may improve the sensitivity and specificity of VOC-based diagnostics for non-small-cell lung cancer. The study emphasizes aldehydes' potential as trustworthy biomarkers for the early diagnosis of lung cancer [27].  
To identify and measure volatile organic chemicals (VOCs) in human breath as possible lung cancer biomarkers, [PERSON] et al. conducted a study. Using gas chromatography-time-of-flight mass spectrometry (GC-TOF/MS) for analysis and SPME for preconcentration, the method produced quick and sensitive detection at parts-per-billion (ppb) levels. Linearity between 0.83 and 234.05 ppb, detection limits between 0.31 and 0.75 ppb, and precision with relative standard deviations (RSDs) below 10% were all displayed by the accuracy-optimized approach. Using sophisticated statistical techniques, the study found important volatile organic compounds (VOCs) linked to lung cancer, indicating that this non-invasive technique is a promising early screening tool [28].  
In order to collect volatile organic compounds (VOCs) from biological materials such as blood, breath, buccal swabs, and urine, [PERSON] et al. devised and refined a headspace SPME approach employing forensic and clinical kits. Using this method, different samples from the same person might be directly compared. VOCs could be detected with great sensitivity using their optimized SPME-GC/MS approach; urine had the highest detection limits while breath samples had the lowest [29].