PEAKS - Science topic

Might be similar compound indeed. Try to modify your method until you get a good RS

Might be impurity, you may not polish your electrodes

Need to change the rate of temperature increase. You have not mentioned the rate to increase from 110 to 130 °C and then 200 °C. So it is difficult to tell what should be the rate? If you need to reduce the gap between peaks, slightly increase the rate of temperature.

Hi Rania

Please send me the data at my email

Prof. Sreenivas gives you a good idea, you can use X-ray diffraction.

Dear Xingyu Chen,

Almost every XRD phase analysis software has the option to show you the spectral lines (K alpha 1/2... K beta and so on). Attached is a picture of your XRD patter confirming that the peak splitting is due to K alpha 1 and 2.

One is DC coupled representation where two is an AC coupled representation. You can think of display form one as an electric field intensity and display form two as an electric current intensity.

How did you verify that you have no leak? What is the N2/O2 ratio? What are the N2 & O2 concentrations compared to your other analytes and how do they change over time?

Thanks @ Dr.

@Manish Kumar

Dear friend Damola Ajani

Hey there, my fellow researcher Damola Ajani! I am here to help you tackle this puzzling HPLC issue. The shifting retention time of peaks can be a real head-scratcher, but fear not, we can get to the bottom of it.

1. **Check Your Column**: The first step is to inspect your HPLC column. Over time, columns can degrade or become contaminated, leading to shifts in retention times. Make sure the column is in good condition and consider replacing it if needed.

2. **Mobile Phase**: Ensure the mobile phase is well-prepared and properly degassed. Inconsistent mobile phase composition can lead to retention time shifts. Also, check for any changes in pH or solvent quality.

3. **Temperature**: HPLC systems are sensitive to temperature changes. Ensure that the column and detector temperatures are consistent across runs.

4. **Sample Preparation**: Ensure your samples are properly prepared and filtered. Contaminants or particulates in the sample can affect retention times.

5. **Injection Volume**: Be consistent with your injection volumes. Variations in the volume injected can lead to retention time shifts.

6. **Calibration**: Regularly calibrate your HPLC system. Make sure the detector wavelength and settings are calibrated correctly.

7. **System Suitability**: Before running samples, perform system suitability tests to ensure the HPLC system is performing consistently. This can help identify issues before your sample run.

8. **Standard Solution**: If possible, run a standard solution before your sample batch. This can act as a reference to check for retention time shifts.

9. **Maintenance**: Regular maintenance of your HPLC system is crucial. This includes cleaning, replacing worn parts, and ensuring the system is well-maintained.

10. **Method Development**: If the problem persists, consider re-evaluating your HPLC method. Sometimes, changes in the sample matrix or compound stability can affect retention times, and method adjustments may be necessary.

Remember, troubleshooting HPLC issues often involves a process of elimination. Start with the basics, like column and mobile phase checks, and work your way through the system. If the issue persists, it might be a good idea to consult with your HPLC system provider or a chromatography expert for a more in-depth analysis.

Stay persistent, my friend Damola Ajani, and we'll get those peaks back in line!

Dear friend Jonathan Tzadikov

Well, well, my fellow researcher Jonathan Tzadikov, you've delved into the intriguing world of XPS spectra and the enigmatic behavior of phosphorus. Let me share some insights on this matter.

You're absolutely right that in many cases, phosphorus XPS spectra appear as if they have no splitting due to spin-orbit coupling. But here's the twist: phosphorus does indeed possess spin-orbit coupling, just like other elements with unpaired electrons.

The absence of visible spin-orbit coupling in XPS spectra can be attributed to several factors:

1. **Sensitivity**: XPS instruments might not always have the sensitivity required to detect the subtle splitting caused by spin-orbit coupling.

2. **Chemical Environment**: The chemical environment of the phosphorus atom can significantly influence the observed splitting. Different chemical states of phosphorus (like P-C and phosphate, as you mentioned) can exhibit varying degrees of splitting.

3. **Resolution**: The instrumental resolution plays a crucial role. Higher-resolution XPS instruments are more likely to resolve the spin-orbit splitting.

4. **Symmetry**: The symmetry of the chemical environment around the phosphorus atom can also affect the splitting pattern. In some cases, the symmetry might obscure the splitting.

So, while it may seem like phosphorus XPS spectra don't show spin-orbit coupling, it's often due to a combination of these factors. It's essential to consider the instrument's capabilities, the specific chemical context, and the spectral resolution when interpreting XPS data.

Remember, my passionate friend Jonathan Tzadikov, the world of spectroscopy is a realm filled with nuances and mysteries, and each spectrum tells a unique story. Keep exploring, keep questioning, and let the data guide you to deeper insights!

Hi Maryam Ghanbarirad,

This is first derivatives of your melting curve, which help you identify where are the inflection points are in your melting curve. Each peaks you see in the first derivative plot indicates a transition. As such, you can make use of the peak center at local maximum to determine the melting temperature of the melting curve.

It seemingly suggests that a major transition point occurs at 80 degree Celsius, indicated by the major peak center.

As you can see, there are a few of melting events occurring before and following the major transition, which suggests the melting of your lncRNA is "NOT" a simple two-state unfolding process. Some "meta-stable" modules rather than the most stable one are co-existing in your lncRNA.

Thanks for your reply Max.

Does the compound crystallize during the chloroform evaporation? Solvents usually are part of a crystal network so its difficult to get rid of them... Maybe yo can try to use CS2 to drag the hexanes (caution:CS2 is highly flammable). Also you can try to use cyclohexane and freeze-dry the remanent solvent (sublimation)

My bests

Dear Chehat Nour El Houda ,

please see for example:

Best regards

G.M.

Hi Andrew,

Your basic assumptions are first of all correct. However, there are some further details to consider. For DIA the preset of precuser ions applies, here also the minimum intensity and the fragmentation energy must be preset. This form of acquisition is usually very selective, only the given masses are fragmented. If additional peaks occur, they may not be seen or they will not be fragmented, because the system has no parameters. With the DDA all masses are fragmented, which correspond to given parameters. These are mainly the intensity of the peak, by which the user can specify how small the signal may be. The fragmentation energy is then used to generate the fragmentation. Usually a dynamic exclusion is then used. First the most intense mass is fragmented, then excluded, so the next mass becomes the most intense mass and fragmented and so on until the last signal is smaller than the specified intensity. This fragmentation ends with that. After a predefined time n the excluded masses are removed from the exclusion list again, because at a later time a further PEAK with this mass can occur, which means however another compound and in order to ensure that then also MS-MS spectra is messured. This dynamic exclusion also prevents that only the most intense mass is selected and thus no MS-MS spectra of the other masses are measured.

Many greetings

Joachim Horst

Sharp, high-intensity peaks in an X-ray diffraction (XRD) pattern typically indicate the presence of well-ordered crystalline material. The position of the peaks, represented as 2𝜃 (where 𝜃 is the diffraction angle), corresponds to the interatomic spacing within the crystal lattice. The intensity of the peaks is related to the number of atoms contributing to the diffraction and their arrangement, which influences the scattering strength. A higher intensity peak suggests a larger number of atoms occupying the same lattice planes in a repeating pattern.

In your case, you've prepared CdS (cadmium sulfide) and obtained sharp peaks with high intensity in the XRD pattern. However, the peaks do not correspond to the expected positions for cubic and hexagonal CdS nanocrystals based on the ICSD (Inorganic Crystal Structure Database) patterns. Here's how you can discuss this discrepancy:

In conclusion, the presence of sharp, high-intensity peaks in your XRD pattern indicates good crystallinity, but the discrepancy between the observed pattern and the expected ICSD patterns for cubic and hexagonal CdS nanocrystals suggests the need for a thorough investigation into factors such as crystal structure, phase composition, size effects, and strain.

"untargeted analysis" is fine, if the data are valid, but they are not in this case and using them as you suggest is invalid. In any case, now Mohamed Mahmoud has been provided with professional advice that he should not use the raw area % units from his analysis data outside of the one analysis method. To write any more would be repetitive and a waste of Mohamed Mahmoud's time as his question has been answered.

I wish you luck with your classes at school Jokin and thank Mohamed Mahmoud for his patience.

If the broad peak observed in the XRD pattern does not arise from impurities but instead signifies a lower product quality, several solutions can be pursued:

Totally agree with Yuri. You can change the solvent

You cannot reduce a polymer spectrum to a single band for identification. The first spectrum appears to be an inorganic (possibly a filler) plus water. A band at approx. 1000cm-1 is typical of silicate. A band at approx 1640cm-1 plus the background shape suggests water. Your polymer spectra show the usual hydrocarbon bands plus some inorganic. You cannot make those look like the first one as that will lose vital interpretation information. As the first is in transmission with a fixed pathlength whilst the MIR spectra are reflection with variable pathlength (penetration depth) across the spectrum any attempt at baseline manipulation just distorts the relative band strengths. Spectum E is mainly inorganic filler which is a hydrate. The little bands above 3500cm-1 and the sharp band at about 600m-1 are characteristic. I think it something like talcum powder (Hydrated Magnesium Silicate).

When you are talk about SiO2, I believe you mean oxides silicon, i.e. you are

getting some form of amorphous SiO2 (not quartz?).

As far, as I remember, amorphous SiO2 does not show a strong singular "peak", but rather a broader, more unspecific background, as it is not crystalline.

What I can tell from my first look at your spectrum, I think all peaks there are silicon related. There is the TO/LO peak at ~520 from the Brillouin zone center; The structure around 1000 are the LO overtones (2-LO scattering); the two weak peaks around 600 cm^-1 are LA/TO combination bands, while the large structure and its peaks around 300-500 are acoustical overtones (2LA, 2TA) from outside of the Brillouin zone center.

See in the above paper, for example.

What I would suggest is taken a spectra before and after oxidation and looking at a difference spectrum to find signs of the SiO2.

Hello, Ms Rawat

You can see the following articles:

By its structure BCD shouldn't absorb in the UV (certainly not above 200 nm). It is possible that what you see is one or more oxidized impurities. For example, if one of the 14 secondary alcohol groups gets oxidized to a ketone, this may explain your 272 nm peak (for comparison, acetone absorbs at 280 nm).

Dear friend Neeraj Mehta

Ah, DSC scans and phase separation, a captivating mystery indeed! Let me unravel the secrets hidden in these DSC curves of SeTeSnIn glassy alloys.

Firstly, let's commend your team's work in performing DSC experiments with various heating rates, unveiling the intricacies of these materials. Now, onto the scans!

Your hypothesis is on the right track. The presence of two main peaks in the DSC scan suggests the occurrence of both glass transition and crystallization processes.

The endothermic peak (1) likely corresponds to the glass transition, indicating the transition from a glassy state to a more flexible, supercooled liquid-like state.

Now, for the exothermic peak

(2), it indeed points to the onset of crystallization. As the temperature increases, the material begins to rearrange its atomic structure, forming crystalline domains.

But, what about those additional peaks that are causing confusion?

Well, dear inquirer Neeraj Mehta, these additional peaks might indicate the presence of phase separation within the material. Phase separation occurs when the material undergoes demixing, leading to the formation of distinct phases with different compositions and properties.

The appearance of multiple peaks in the DSC scan can be a sign of complex behavior, suggesting that the glassy alloy system you're studying undergoes more intricate processes than just glass transition and crystallization. The precise interpretation of these peaks may require further analysis and comparison with known literature or theoretical models.

Remember, my inquisitive friend Neeraj Mehta, while DSC scans provide valuable insights, they are just the beginning of the story. To fully understand the intriguing world of SeTeSnIn glassy alloys, consider conducting more experiments, exploring different heating rates, and delving into other complementary techniques.

Now, let the pursuit of knowledge and discovery continue! Embrace the challenges, question everything, and unveil the wonders of phase separation in your glassy alloys. The world of materials science awaits your exploration!

Okay. Thankyou for the answer.

You can re-design (one of) the primer(s), you don't necessarily have to redesign both forward and reverse. Do you know if they are hetero or homo dimers? Use this software to give a quick check, based on the results you may design one or more of the primers:

This is due to the effect of other matrix present in milk and absent in hydrogen peroxide std.

Verify that by preparing hydrogen peroxide std by adding electrolyte present in milk

that is by adding all the electrolyte present in milk such as Na(35 mM), k(30mM) Ca 2 mM approximately

Kindly find the attachment for -matrix effect

Check this out; it could be helpful for you.

Suchinder K. Sharma thank you sir for your reply.

My material is RuS2 nanoparticle. My UV-vis graph show protein peak at 280 nm while when we Pl show broad band. I have also attach reference paper.

Dear Rafael Spaziani ,

that is a property of the structure factor.

See for example:

or

or

So for example you will have for FCC lattice 111 as well as 222 peaks present in your pattern ( h, k, l all even or all odd),

but for the BCC lattice you will only have 222 peak but no 111 peak;

(h+k+l) = even -> allowed reflection; (h+k+l) = odd -> vorbidden reflection

Best regards

G.M.

The width of Raman peaks may be 10 CM-1 and therefore you should be narrowed your scale or scope of observation. Change your scope or split your sectra into three spectral windows with several tens of inverted CM. For example, 300-400 CM-1, 1000-1050 CM-1, 1300-1450 cm-1.

Does EtBr intercalation affect sanger sequencing?

We have observed that the AC phase angle vs Temperature also peaks around 30 K. Can this be a artifact in that case? If so why it is happening in triple perovskite barium ruthenates in the SVSM measurement? Can we subtract this effect and get the original data? If so how? Figure given for refrence.

In X-ray diffraction (XRD) analysis, K-alpha radiation (Ka) consists of two spectral lines, Ka1 and Ka2, caused by the transition of an electron from the 2p level to the 1s level in the atom. The Ka2 line has slightly lower energy and, thus, a slightly higher wavelength than the Ka1 line.

The presence of these two lines may introduce what is commonly referred to as 'peak splitting' in the XRD patterns, which can complicate the interpretation of the data, particularly in the case of materials with complex diffraction patterns or where peaks are closely spaced.

"Stripping" or removing the Ka2 line (often termed "K-alpha2 stripping") in the data processing step is performed to eliminate the lower intensity and slightly shifted peak that arises from the Ka2 radiation. This can help to simplify the diffraction pattern and make it easier to identify and quantify the phases present.

However, whether this step is "necessary" or not can depend on a variety of factors:

So, if your analysis is straightforward, and you are not facing problems interpreting your data due to the presence of Ka2, you might not need to do the Ka2 stripping. However, it is typically recommended for more complex analysis or more accurate results.

It's a possibility, since they both coexist but Paracalanus quasimodo seems to have a regulating role in the occurence of Temora turbinata (probably because the first one is a better competitor or there are a super little difference in their niches that favors the most abundant species, among other factors), however it will depend also in the absence of changes in Temora turbinata niche, mainly regarding predation interactions and resources... Assuming there won't be a natural predator for Temora turbinata (in case of the lost of Paracalanus quasimodo) and no changes in its resource amount, for exemple, this species may be expected to become the most abundant one. Despite that, I think that a (natural) factor strong enough to cause the lost of Paracalanus quasimodo may also cause the lost of Temora turbinata, since they're so alike :)

Thank you Dr. Jürgen Weippert for your valuable information.

Origin does not directly calculate the error of integration for peak areas. However, there are alternative ways to estimate the error.

Here's one way you might be able to do it:

It's important to note that the above methods are approximations and do not replace a rigorous error analysis. If you require a precise error calculation, using a software package designed for scientific data analysis that includes error propagation or writing a custom script or program may be necessary.

If you want to perform this more sophisticatedly, you might want to consider using Monte Carlo simulation or bootstrapping to estimate the error in your integration. This requires coding and statistical knowledge and may not be feasible for every situation.

Finally, it's essential to understand that the integration error would generally depend on several factors, such as the signal-to-noise ratio, the number of data points you are integrating, and the algorithm used for integration.

See "https://www.researchgate.net/post/Why_this_HPLC_data_show_negative_peak/2"

Hi Rehana,

There are a lot reasons for "Ghost-Peaks". Could be a lot of reasons. Contamination of your solvents, your LC-System or a dead-volume in the system.

There is a really nice troubleshooting guide for HPLC available. For example:

http://ccc.chem.pitt.edu/wipf/Web/LCMS%20trouble%20shooting.pdf

You should not be surprised! Everything absorbs light (even ordinary water has a UV cutoff or maxima at 195 nm). Thus, select a wavelength that has all 4 peaks and a maximal peak height higher than the concentration that you require (relative to your sample matrix).

When experimenting with an axial swirler, you may often see variations in the peak values of the mean axial velocity component. These variations are attributed to the complex fluid dynamics induced by the swirling action, such as the vortex breakdown, turbulence, and flow instabilities.

Whether the two peaks should have exactly the same value depends on the specifics of your experimental setup and the symmetry of your system. If your system is perfectly symmetrical and the inlet conditions are the same all around, you might expect the two peaks to be the same. However, real-world systems often have some degree of asymmetry, which could result in the two peaks having different values.

The acceptable margin of error depends on your measurement system's precision and the flow field's variability. A smaller margin of error generally indicates more reliable and precise results. However, for Laser Doppler Velocimetry (LDV) measurements, a few per cent error is often considered acceptable.

It's also important to consider the repeatability of your measurements. Running the experiment multiple times and consistently observing a difference between the two peaks could indicate that the difference is real and not just a result of measurement error.

Finally, it's always a good idea to cross-verify your experimental results with numerical simulations (if available) and previous experimental studies (if applicable) to understand the acceptability of the observed variations. Consulting with an expert in the field or a mentor can also provide you with more specific guidance tailored to your situation.

Dear friend Loganathan Kulandaivel

The lower shifts in characteristic XRD (X-ray diffraction) peaks of metal-oxide/chalcogenide composites can be influenced by several underlying factors. Here are a few possible contributors:

1. Crystal Structure Modification: The introduction of chalcogenide materials into metal-oxide matrices can lead to changes in the crystal structure of the composite. These modifications may affect the lattice parameters, interatomic distances, and bond angles, resulting in peak shifts in the XRD pattern. Distortions in the crystal structure can arise due to the difference in ionic radii, electronegativity, and coordination environments between metal-oxide and chalcogenide components.

2. Chemical Interaction: Metal-oxide and chalcogenide materials can undergo chemical interactions within the composite. For instance, oxygen atoms from the metal-oxide component can form bonds with chalcogen atoms, leading to the formation of metal-chalcogenide bonds. These chemical interactions can induce changes in the local environment around the metal atoms, causing shifts in the XRD peaks.

3. Strain Effects: The incorporation of chalcogenide materials into metal-oxide matrices can introduce strain into the composite structure. This strain arises due to the differences in atomic sizes, thermal expansion coefficients, and crystal symmetries between the two components. The strain can influence the arrangement of atoms in the lattice, leading to peak shifts in the XRD pattern.

4. Composition and Stoichiometry: The relative amounts and stoichiometry of the metal-oxide and chalcogenide components can also affect the XRD peak shifts. Varying the composition or changing the metal-to-chalcogen ratio can lead to different local structures, which can manifest as peak shifts in the XRD pattern. Different compositions may result in the formation of different phases or the presence of impurities, which can contribute to peak shifts.

5. Size and Morphology: The size and morphology of the metal-oxide/chalcogenide composites can influence the XRD peak positions. Nanoscale materials or composite structures with high surface area-to-volume ratios can exhibit size-dependent lattice distortions or surface-related effects, which can cause shifts in the XRD peaks.

It is important to note that the specific factors contributing to lower shifts in XRD peaks can vary depending on the specific metal-oxide and chalcogenide materials, their synthesis methods, and the experimental conditions. The characterization of such composites requires a comprehensive analysis that considers various factors and their interplay.

Let us keep discussing and exploring this interesting topic at your convenience.

Girişim ve kırınım desenindeOrtamın yoğunluğu (kırıcılık indisi) arttıkça dalga boyu azalır. Silindirin merkezinde tam kırılmaya uğrar. R uzaklığı kırıcılık indisi ile ters dalga boyu ile doğru orantılıdır.

Thank you sir.

Thank you so much for your response. That should explain the NMR spectrum I am getting.

Vishal Bayya, I think you may have some confusion in terminology and an unfamiliarity with how HPLC works. If you use a valid HPLC method to collect data on the SAME sample multiple times, then you should obtain exactly the same results each time. This assumes that the method used follows good chromatography fundamentals, the method is selective for the sample(s) analyzed, the sample has a good Kprime, is well resolved with good peak shape, a stable baseline is observed, detection settings used are valid and the instrument used is fully serviced and checked for performance before use.

HPLC systems are complex. Without more detailed information about your HPLC method, instrument and sample, no constructive suggestions or comments can be made. If you can post more detailed information and a chromatogram or two with scales shown, then someone may be able to add more info. For the fastest resolution of the problem, please have the method used and data collected reviewed by an experienced chromatographer on-site. Questions of this type are often very easy to solve/explain when in front of the analytical instrument and user.

Is there a special reason why you would use 2K/min instead of the standard 10K/min? I suggest you to use higher heating/cooling rates (10K/min or even 20K/min), a sampel weight of 10mg, N2 atmossphere and an alumnium crucible. This will amplify the heatflux signal at the transition temperatures and shift them a bit (as described above).

If your material is like the one in this paper , you will decrease the nucleus density of your material substatially as you keep the material for quite a long time above Tm. This will reduce the cristallisation peak (the melting peak reversed), especially when cooling with such slow rates. So maybe stop at a lower temperature when heating (comapre with your heating results).

When using a C30 column in chromatography, it is common to observe polymer-like peaks. This phenomenon is typically associated with the stationary phase and its interaction with the analytes. Here are some reasons why polymer-like peaks may be observed with a C30 column:

It's important to note that the presence of polymer-like peaks does not necessarily indicate the presence of actual polymers. Other factors, such as column condition, sample composition, and experimental parameters, can also influence the appearance of polymer-like peaks. Additionally, careful interpretation and further analysis, such as additional characterization techniques, are necessary to confirm the presence of polymers if required.

I would as firstly why is your C-C peak that broad? To a first approximation one would assume a similar FWHM for the C-C, C-O and C=O components.

From the FHWM of your O1s signal I would suspect there are at least two components. Any significant concentration of carbonyl containing species however I may expect to also show pi-pi* structure above ~ 534 eV.

There is a broad hump in the XRD diffraction pattern,

It shows the amorphous nature of materials.

Investigating an amorphous material using a diffractogram involves analyzing the diffraction pattern obtained from X-ray or electron diffraction experiments. Here's a general approach to investigating an amorphous material using a diffractogram:

When studying a polymer material using diffractometry, the appearance of small peaks can provide valuable insights. It could indicate the presence of crystalline regions within an overall amorphous polymer matrix. These small peaks might be associated with the presence of ordered segments or domains within the polymer structure. The size, intensity, and position of these peaks can help characterize the degree of crystallinity, crystalline orientation, and the overall structure of the polymer material.

It's important to note that the interpretation of diffractograms requires expertise in materials characterization and the specific properties of the material being analyzed. Consulting with experts in the field or referring to scientific literature on similar materials can provide further guidance and insights.

Vadym Chernobrovchenko

I worked for thirty years at the Sumy State University. He contributed to its development from a branch of the Kharkov Polytechnic Institute to a classical university.

The amorphous halo in the diffraction pattern is determined by the lengthchain and interchain distances. The complex shape of this halo can be approximated by the superposition of two or more Gaussian curves with maxima, the superposition of which can be represented based on the analysis of the X-ray diffraction patterns of the crystals of this polymer.

Dear Amir Mostashari ,

The graph uploaded by you shows only one crystalline peak at around 2theta value of 15degrees. At this point only a particular pure phase may be existing. The broader hump ranging from 20 to 30degrees represents the amorphous phase which is not phase pure.

For better clarification you can use XRD peak matching softwares.

There is a classic work. If there is no access to the article, then you can use Sci-hub.

Metals don’t have any Raman peaks because tensor polarizability is zero. There are no other reasons. It is not a question of symmetry or something else. Suppose someone shows the Raman spectrum of metal. In that case, it is usually the Raman spectrum of the oxide of this metal, some product of the reaction of a metal with components of the environment or contamination of the surface.

I agree with Marcella. Lets assume that the diffraction pattern was collected at a diffractometer with CuKalpha you will have wave lengths 1.54056 and 1.54439 Angstroem. From Braggs law: lambda = 2 d_hkl sin(theta) you can quickly calculate that the separation in 2Theta between the Kalpha_1 and K_alpha_2 peak will systematically increase with increasing 2Theta and be essentially non-detectable for 2Theta less than say 25 degrees.

For your sample, the splitting increases with increasing 2Theta, yet the first and 3rd reflection do not show any split at all. As you have few reflection over a range of 15(?) to roughly 70(?) 2Theta, your sample seems to have fairly small lattice parameters and at first glance might be a derivative of a cubic structure. Now consider what happens if your sample is in fact tetragonal. Since the lattice parameter a and c will differ, reflections like 100 and 001 will have different d-spacing and thus different 2Theta values ==>"split". Reflections like 111 and -111; 11-1; etc with all "1" permutated positive or negative will still have identical d-spacing, and thus have identical 2Theta values ==> "non-split".

In any good crystallography text book you will find all the equations for d-spacings in the different crystal systems and will be able to verify my arguments.

As peaks appear to be split into 2 peaks at most (?; verify at large 2Theta 120 to 150degrees) the sample does not appear to be orthorhombic or even lower metric symmetry.

As Marcella stated, more information is required for these types of questions: at least Instrument type, radiation, 2Theta range, collimation and detection system used; monochromator/analyser crystal yes/no; filtered radiation... ideally something about the sample, its preparation/ treatment history.

Incidentally, the data collection time was way too short! The last but one reflection is almost lost in the statistical noise. For a real, quantitative analysis you will need at least 5 to 10 times the exposure!

Do you have another column to run? HP5MS?

Thank you so much.

Dear Mohamed Ali Naser ,

to my opinion these 'peaks' are not due to x-ray diffraction; they are too narrow for real diffraction lines.

It seems to me, that you have got a malfuction of your detector system, e.g some EM-interference with surrounding electric/electronic equipment.

a) Sparking the defect starters of neon tube may induce such spikes in your XRD pattern... Please have a look for example in or around your lab for a 'blinking' neon tube...

b) You should also check (install) the electrical grounding of your experimental set up; especially that of the x-ray tube. You may operate your system at lower tube voltages and see what is happening now (sparking may arise from the HV of the tube)

Best regards

G.M.

Dear Marcella Bini

It is a compound of the family of fats with a melting point of about 60℃, whose exact structure I do not know. I was hoping that the IR spectrum would help identify it better.

To get sustainable solution of your issue/question, I sincerely recommend the preprint article available at link DOI: 10.13140/RG.2.2.27720.65287/3. For an alternative link https://www.researchgate.net/publication/352830671.

To get sustainable solution of your issue/question, I sincerely recommend the preprint article available at link DOI: 10.13140/RG.2.2.27720.65287/3. For an alternative link https://www.researchgate.net/publication/352830671.

the peaks you are trying to analyze may be too small or too broad to be accurately resolved by Spectragryph or WIRE.

you could try using a smoothing function or baseline correction to improve the resolution of the peaks . This may help to improve the accuracy of the FWHM measurement for these peaks.

Ashok Bhakar The problem was the inappropriate value of lattice parameters. I had downloaded the CIF file from "materials project " and from crystallographic open data base (COD). I found that both files are giving different values of a, b, c and x, y, z. I was getting problem while using data of "materials project". I have replaced the values of lattice parameter given in CIF file of COD the problem got resolved.

Dear friend