The chemical composition of nanomaterials is characterized using wide analytical methods. Elemental analysis (EA) is commonly used for the analysis of C, N, O, S, and X (halide, F, Cl, Br, and I) . It is called also 'CHNX' analysis. It gives usually the ratio of the elements within organic-based nanomaterials with an acceptable standard deviation (SD) of 0.3%. EA using the combustion technique is mainly used for organic compounds. The chemical composition of organic moieties can be characterized using chemical methods such as the sodium fusion test (Lassaigne's test). Techniques such as mass spectrometry (MS) can be used for the chemical composition of organic species directly based on molecular weight via ionization (Table ) . Mass spectrometry can be used for organic and inorganic species with high ionization affinity. The ionization of inorganic species is hard. Thus, powerful techniques are widely used for the ionization of inorganic species via the conversion of the element in the material into the atom. The conversion or ionization of the target element into an atom can be achieved via different methods such as flame atomizers, plasma (temperature of 6000-10000 K), glow discharge atomizers, and others. The composition of inorganic-based nanomaterials is characterized using techniques such as inductively coupled plasma mass spectrometry (ICP-MS), ICPoptical/atomic emission spectrometry (ICP-OES/AES) , and atomic absorption/emission spectroscopy (AAS/AES) . Most of these methods are used for the determination of the elements in solution. However, solid-state samples can be evaluated via methods such as electrothermal vaporization. The chemical composition of the surface can be determined using techniques such as X-ray photoelectron spectroscopy (XPS) , energy dispersive X-ray (EDX), and X-ray fluorescence (XRF) . The important aspect of these analyses is the penetration depth of these techniques. EDX and XPS analysis is suitable for the thickness of 2 μm and 10-100 Å, respectively. Surface analysis techniques such as EDX are not suitable for light elements such as C, N, and O.