Could you please clarify your question ? I'm guessing you want to analyze cellulose based fibers (from wood or annual plants) for elements other than C,H,O (and ignore the sugars). Is that correct ?

Notwithstanding the cellulosic part, you're then asking for a full elemental anlysis, which will require various techniques. Depending on the cellulose source, you may have anything from 0.1 to 2% ash after calcination : you will be dealing with trace elemental analysis in any case and may require various equipment depending on your target elements.

Most of the elements, starting from Lithium will be better determined using ICP-MS (or ICP-OES if you manage to calcinate lots of material to obtain enough ash to concentrate). Exceptions to this would be those elements that can be lost by combustion or uncontrolled digestion (Mercury, Arsenic, Selenium and of course Nitrogen, Sulphur...) and those that cannot be analyzed using ICP (mostly Halogens).

In case you hace plenty of material and time : calcinate your sample until you get at least 100 mg ashes. You can then produce a glass disk using alkaline fusion and analyze it using XRF. You'll get the major elements that withstanded calcination and fusion : all metals, all alkali and eart-alkali, which is already pretty good for cellulosic materials.

Nitrogen is "simple" : Kjeldahl, Dumas or CHNS elemental analyzer.

Chlorine can be estimated through hot water extraction and Ion Chromatography or ISE. Or you can use a Chlorine analyzer.

Sulphur can be analyzed using Sulphur analyzers or even ICP-OES using UV excitation after digesting the sample (500mg to 1g in nitric acid + some water or hydrogen peroxide works well for me). Other methods exist in the literature, which are for instance in use in the paper industry.

SEM-EDX is quick but mostly not adapted to analyzing cellulose : its limit of detection is ca. 0.1% atomic. Not a lot of elements that can be seen in natural fibers samples (especially if you deal in bleached cellulose...).

If you want more details, please narrow your questioning.

It depends on the type of fiber origin?

Is it plant fibers, animals, or other origin?

the attached chemical structure of the natural fibers may help you

you can find answer of your question in the following article

Natural Fibers as Sustainable and Renewable Resource for Development of Eco-Friendly Composites

Article Natural Fibers as Sustainable and Renewable Resource for Dev...

Chemical Structure

Chemical Composition of Natural Fibers and its Influence on their Mechanical Properties was studied and presented by Komuraiah, A. ; Kumar, N. Shyam ; Prasad, B. Durga

Please review the following

Mechanics of Composite Materials, Volume 50, Issue 3, pp.359-376

Pub Date: July 2014 DOI: 10.1007/s11029-014-9422-2

Recently, Sagar Chokshi performed a review study about

Chemical Composition and Mechanical Properties of Natural Fibers

With the aid of the following reference, you can find what you need

Article Chemical Composition and Mechanical Properties of Natural Fibers

Pierre Caulet I need to prove that the incoming raw material from the supplier is the one I ordered. I ordered for Pineapple Leaf Fiber. So, right now I have decided to conduct FTIR analysis which qualitatively proved it. But it doesn't give the quantitative information on how much alpha-cellulose, hemicellulose and lignin the fiber contains.

OK, so you do not want elemental analysis, but rather the breakdown of your cellulosic material into its main components.

This is a different ballgame and you'll need other techniques to achieve that. None too complicated I guess, if this is for raw material control.

There have been a lot of methods developed in the Pupl&Paper industry to study and quantify celluloses, hemicelluloses and lignin.

One of the best book ever on the subject would be the one by Sjöström and Alén, "Analytical Methods in Wood Chemistry, Pulping and Papermaking".

See for instance : Book Analytical Methods in Wood Chemistry, Pulping, and Papermaking

Traditional methods for obtaining a lignin "content" in the Pulp industry are the Klason lignin (acid solubilization) but it does not work well with annual plants due to the presence of too many proteins, and the Kappa number or Chlorine number(oxidations) for which I have no experience with annual plants.

Anyway, you should have only very small amounts of lignin in annual plants, especially in the leaves...

For more details, go and take a look on TAPPI's website and look for the TAPPI methods for those.

In the Pulp&Paper industry, Alpha-Cellulose is traditionally defined as the insoluble part after treated pulp (separated and dispersed fibers) with 17.5% NaOH at room temp.

Alpha-Cellulose content can also be controlled following ISO 699 guidelines : 18% NaOH treatment and separation of the soluble fraction (called S18) and the insoluble fraction (called R18). This is a more common way of separating alkali soluble/insoluble material in fibers.

Hemicelluloses will be part of the soluble fraction in alkali solutions (S18), but they might not be the only ones (lignin might, pectins might).

But some hemicelluloses will not be soluble as well : for instance using KOH will not dissolve glucomannans...

So I suggest that you start with applying the ISO 699 with NaOH 18% to start with, and stick to S18 soluble and R18 insoluble fractions.

chemical analysis, TAPPI T 203CM - 99 (alpha cellulose), T222 om-02 (lignin), aquueous alkali extraction (hemicellulose)

Thanks everyone

Chemical composition analysis at South India Textile Research Association

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Article Tailor-Made Biosystems - Bacterial Cellulose-Based Films wit...

There are several methods that can be used to determine the chemical composition of natural fibers, including elemental analysis techniques such as SEM-EDX (scanning electron microscopy-energy dispersive X-ray spectroscopy) and FTIR (Fourier transform infrared spectroscopy). These techniques can provide information about the elemental composition of the fibers, including the presence and relative proportions of elements such as carbon, hydrogen, and oxygen.

To obtain a more detailed understanding of the chemical composition of natural fibers, it may also be necessary to use other analytical techniques, such as chemical analysis methods or spectroscopic techniques. These methods can provide information about the specific functional groups or compounds present in the fibers, as well as their relative proportions.

Some common chemical analysis methods that can be used to determine the chemical composition of natural fibers include:

It is important to carefully choose the appropriate analytical method based on the specific goals of the analysis and the characteristics of the fibers being studied. It may also be necessary to use a combination of different methods in order to obtain a comprehensive understanding of the chemical composition of the fibers.