_applied sciences_  
_Editorial_  
**10 th Anniversary of Applied Sciences-Invited Papers in Chemistry Section**  
**[PERSON]**  
Faculty of Science, Charles Sturt University, Albury, NSW 2640, Australia; [EMAIL_ADDRESS]; Tel. : +61-2-6051-9681  
**Abstract**  
MDPI's _Applied Sciences_ reached a remarkable milestone in 2020 when the 10 th volume of the journal was published and an impact factor of 2.474 was achieved. To celebrate this special occasion, the Chemistry Section has produced a special issue based mainly on invited papers to mark \"The 10 th Anniversary of Applied Sciences\". This Special Issue consists mainly of 12 original research articles and 1 comprehensive review featuring important and recent developments in analytical chemistry, environmental chemistry, nanomaterial chemistry, polymer/coating chemistry, drug delivery chemistry, and flavonoid chemistry. Three of the featured articles are in the broad area of _analytical chemistry_. In one of these papers, [PERSON] et al. [1] explored the use of a mixed cationic-reverse phase column coupled to high-resolution tandem MS (HR-MS/MS) for the analysis of small highly polar metabolites in biological fluids at low concentrations. They successfully retained and separated trimethylamine N-oxide (TMAO) and the isobaric molecules beta-methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB). When applied to plasma and urine samples, they achieved linear concentration ranges of 50-1000 ug/L and 500-10,000 ug/L for TMAO and both BMAA and DAB, respectively. The effectiveness of the method was also investigated for biologically relevant compounds and those with a wider range of polarities. This approach consequently enabled the simultaneous analysis of a larger range of metabolites, from very small and polar compounds to quite lipophilic molecules. In another study, [PERSON] et al. [2] employed ultrasound vortex-assisted dispersive liquid-liquid microextraction and gas chromatography coupled to ion trap mass spectrometry for the determination of non-steroidal anti-inflammatory drugs (NSAIDs) in animal urine samples. The urine samples were initially treated with \(\beta\)-glucuronidase/acrylsulfatase before extracting the NSAIDs with CH\({}_{2}\)Cl\({}_{2}\) by the ultrasound vortex-assisted dispersive liquid-liquid microextraction method. They achieved an enrichment factor of about 300-450 times by this approach, with 94.1 to 101.2% recoveries and a relative standard deviation (RSD) of \(\leq\)4.1%. The achieved limits of detection (LODs) and limits of quantification (LOQs) were 0.1-0.2 ng mL\({}^{-1}\) (RSD \(\leq\) 4.5%) and 4.1-4.7 ng mL\({}^{-1}\) (RSD \(\leq\) 3.5%), respectively. [PERSON] et al. [3] synthesized rapid and cheap MoS\({}_{2}\) nanostructures on paper substrates through microwave-assisted hydrothermal synthesis for the production of low-cost near-infrared photodetectors. The best results were obtained with the interdigital MoS\({}_{2}\) photodetector by using photoactive MoS\({}_{2}\) nanosheets synthesized at 200 \({}^{\circ}\)C for 120 min. They achieved a responsivity of 290 mA/W, detectivity of 1.8 \(\times\) 10\({}^{9}\) Jones, and an external quantum efficiency of 37% with the photodetector. Another broad area which is well represented in this special issue is _environmental chemistry_, with four featured articles. [PERSON] et al. [4] reported on the weekly and longitudinal elemental variability in hair samples collected from non-occupationally exposed subjects. Neutron activation analysis was used to determine 30 elements in hair samples collected from different locations on the scalp. Notable differences were observed among samples between the proximal and distal sections. A comparison with other studies was used to establish the relationships and the differences caused by different ethnic origins, lifestyles, diets, and climates among different young populations. In another study, [PERSON] al. [5] explored the use of bottom ash derived from the co-combustion of municipal solid waste and sewage sludge as a stabilizing agent.