Comptes Rendus
Chimie
Sandra Tamosaityte, Milda Pucetaite, Arunas Zelvys, Sonata
Varvuolyte, Vaiva Hendrixson and Valdas Sablinskas
Raman spectroscopy as a non-destructive tool to determine the
chemical composition of urinary sediments
Online first, 28th September 2021
<https://doi.org/10.5802/crchim.121>
Part of the Special Issue: Microcrystalline pathologies: Clinical issues and
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Comptes Rendus
Chimie
Online first, 28th September 2021
https://doi.org/10.5802/crchim.121
Microcrystalline pathologies: Clinical issues and nanochemistry /Pathologies
microcristallines : questions cliniques et nanochimie
Raman spectroscopy as a non-destructive tool to
determine the chemical composition of urinary
sediments
Sandra Tamosaitytea, Milda Pucetaite a,b, Arunas Zelvys c, Sonata Varvuolyte c,
Vaiva Hendrixson cand Valdas Sablinskas ∗,a
aFaculty of Physics, Vilnius University, Sauletekio al. 9, LT-10222 Vilnius, Lithuania
bDepartment of Biology, Lund University, Sölvegatan 37, 22362 Lund, Sweden
cFaculty of Medicine, Vilnius University, M.K. Ciurlionio g. 21, LT-03101, Vilnius,
Lithuania
E-mails: s.tamosaityte@gmail.com (S. Tamosaityte), milda.pucetaite@gmail.com
(M. Pucetaite), arunas.zelvys@santa.lt (A. Zelvys), sonata.varvuolyte@mf.vu.lt
(S. Varvuolyte), vaiva.hendrixson@mf.vu.lt (V. Hendrixson), valdas.sablinskas@ff.vu.lt
(V. Sablinskas)
Abstract. Urolithiasis is a common disease worldwide, but its causes are still not well understood. In
many cases, crystalluria provides an early indication of urinary stone formation, and characterisation
of the urinary deposits could help doctors to take early preventative measures to stop their further
growth. Nowadays, the gold standard for the analysis of urinary deposits is optical microscopy, but the
morphology-based information it provides can often be unreliable and incomplete, particularly for
deposits with no defined crystalline structure. In response to the need of a more attested method, we
used Raman spectroscopy to determine the chemical composition of urinary deposits and urinary
stones of 15 patients with urolithiasis in order to find out whether direct correlation between the
composition of the corresponding stones and the deposits exists. We found that the main chemical
compounds typically constituting urinary stones also form the deposits and that their composition
correlates in eleven out of fifteen cases. However, brushite deposits that we found in two cases did
not result in brushite, but mixed calcium oxalate monohydrate and phosphate stones. Overall, Raman
spectroscopy is an informative and reliable method that can be used for analysis of urinary sediments
for early diagnosis of urinary stone formation.
Keywords. Urolithiasis, Crystalluria, Urinary stones, Urinary sediments, Raman scattering, Spec-
troscopy.
Online first, 28th September 2021
∗Corresponding author.
ISSN (electronic) : 1878-1543 https://comptes-rendus.academie- sciences.fr/chimie/
2Sandra Tamosaityte et al.
1. Introduction
Urinary stone disease is a common condition, and
its prevalence is increasing worldwide. Current
incidence varies among different countries from
1% to 20% and can constitute major costs for health
care systems as well as significantly decrease the
quality of life for people with the disease [1,2]. Early
diagnosis could aid in prescribing treatment that
prevents urinary stone growth and avoid more ex-
pensive and, in severe cases, invasive stone removal
procedures [3].
Urinary stone formation processes are believed
to be caused by urinary saturation with typical uri-
nary stone forming materials such as calcium ox-
alate, uric acid, various urates, calcium phosphates,
amorphous phosphates, and magnesium ammo-
nium phosphate hexahydrate (struvite). This leads
to formation of urinary deposits (or sediments) that
are indicative of urolithiasis [4–6]. Less commonly,
urinary deposits can also be constituted from cys-
tine [7], various lipids [8], and metabolites of some
drugs [9,10] that contribute to the stone formation
processes. Qualitative chemical analysis of chemi-
cal composition of urinary sediments plays an im-
portant role in taking early preventive measures to
stop urinary stones from forming or growing [4,6,11].
Such analysis is usually challenging because of their
small size, brittleness and inhomogeneity [12]. Opti-
cal microscopy is currently considered the gold stan-
dard for this purpose, and it is the only method used
in clinical practice [10,13]. Visual morphology-based
inspection of urinary sediments is, however, not pre-
cise enough, since it is based on the examination
of the shapes of sediments and cannot be reliable
when the structure of these sediments is atypical or
amorphous or consists of multiple components.
Alternative methods to optical microscopy are
still in high demand in the medical field for qual-
itative and quantitative chemical analysis of uri-
nary deposits. The chemical composition of urinary
stones is routinely analysed using vibrational spec-
troscopy [12,14–20], X-ray diffraction [19,21], and
scanning electron microscopy with element distri-
bution analysis (SEM-EDAX) [22]. For urinary sedi-
ments, SEM-EDAX experiments have also been car-
ried out, but information about the chemical com-
position of the sample provided by such experi-
ments are not accurate enough [23]. More reliable
results have been obtained by means of infrared
(IR) microspectroscopy, but the quality of the re-
sults is very dependent on the size of the sediment
under study, which is also limited to approximately
10 µm [12,24,25]. In addition, IR spectra of urinary
deposits can be significantly affected by Mie scatter-
ing, which seriously obstructs analysis [24]. Finally,
larger crystals cannot be measured in the transmis-
sion mode of the IR microscope without additional
sample preparation, and the specular reflection sig-
nal that could be used instead suffers from spectral
distortions that are difficult to correct for [14]. Ra-
man spectroscopy is a method complementary to IR
microspectroscopy, but it offers higher spatial reso-
lution, meaning that smaller samples can be anal-
ysed [25,26]. It also allows the challenges posed by
analyzing Mie scattering or reflectance IR spectra to
be overcome. The main disadvantage of the method,
fluorescence that can overwhelm the Raman scatter-
ing signal, can be suppressed or even eliminated by
using a Fourier transform (FT) Raman spectrometer
that employs a near-IR (NIR) laser for excitation of
Raman scattering.
In Raman spectroscopy experiments [27], a
monochromatic light source, usually a laser, is em-
ployed to excite the molecules of a sample. Fluores-
cence that interferes with the Raman signal origi-
nates when a molecule is excited to higher electronic
energy states. It happens when the energy of the laser
photons exceeds the gap between the electronic en-
ergy levels of the molecule. This is especially criti-
cal issue for “real life” samples the molecular com-
pounds of which might not possess electronic tran-
sition in the visible spectral region but very often
are contaminated with fluorescent impurities such
as various pigments. Such impurities cannot always
be removed from the sample, as is the case for uri-
nary sediments [28,29]. Using lasers of longer wave-
length reduces the probability of such electronic
excitation and, in turn, occurrence of fluorescence.
Since over the past decades NIR laser sources have
become widely available, their implementation in
Raman spectroscopy experiments has been gaining
popularity in various fields, especially in biology and
medicine [30]. It has been used in a few case stud-
ies for identification of unrecognized crystals in the
urine of patients suffering from gout [31] and pso-
riatic arthritis [32]. It has also been recently shown
that a dispersive Raman spectroscopy system using
C. R. Chimie — Online first, 28th September 2021
Sandra Tamosaityte et al. 3
785 nm excitation can be useful for the identification
of small urinary crystals in patients with urolithia-
sis [33,34]. Automatic analysis of single-component
deposits has also proven to be possible [33]. In
this work, we specifically examined the potential of
FT–Raman spectroscopy with 1064 nm laser excita-
tion to explore the chemical composition of urinary
sediments. This approach can further improve the
sensitivity for identifying such sediments by reduc-
ing fluorescence background. Importantly, we inves-
tigated the chemical composition of urinary stones
from the same patients with urolithiasis to determine
whether direct correlation between the composition
of the corresponding stones and the deposits exists.
2. Material and methods
For the duration of one year of the project de-
scribed here, urine samples of every patient with
acute uronephrolithiasis hospitalised at the Urology
Centre of Vilnius University Santaros Clinics were
collected—fifteen in total. The samples were inves-
tigated with NIR Raman spectroscopy. The chemical
composition of the urinary stones removed from the
same patients was also checked by means of FTIR
spectroscopy. For the stones, this bulk analysis tech-
nique allows better identification of overall compo-
sition than Raman spectroscopy, which yields infor-
mation on micrometer-sized areas that are analysed.
Urine samples were centrifuged in order to sep-
arate the urinary crystals. The precipitates were fil-
tered on Whatman ashless grade 542 filters for 24 h
at room temperature to remove the remaining liquid.
All particles larger than 2.7 µm in diameter remained
on the surface of the filter, but only the larger ones
(typically >100 µm in size) were collected with the
aid of a small needle. Those particles were transferred
to the surface of a silver mirror, a typical substrate in
spectroscopic analysis that does not produce any Ra-
man signal of its own [35]. This procedure is suitable
to collect single crystallites for Raman spectroscopic
analysis. The use of artificially synthesised magnetic
nanoparticles which adhere to the crystallites in
urine solution has been shown to provide possibil-
ity to automatically detect, hold and release them for
Raman analysis [33], which provides potential for fast
identification of many urinary deposits in the future.
Spectra were recorded with a MultiRAM (Bruker
Optik GmbH, Ettlingen, Germany) FT–Raman
spectrometer equipped with microscope stage and
a gold-plated mirror objective (focal length 33 mm)
which yields the diameter of the focused laser beam
on the sample equal to 100 µm. Samples were excited
with a Nd:YAG laser having a wavelength of 1064 nm
to produce Raman scattered radiation, which was
collected by a liquid-nitrogen–cooled Ge diode de-
tector. The spectra were collected at a resolution of
5 cm−1. Depending on the size and morphology of
the urinary deposits, 200 to 170,000 scans were ac-
quired and averaged for a single resultant spectrum.
Also, the power of the excitation laser was varied be-
tween 5 and 600 mW in order to avoid thermal dam-
age caused by focused NIR laser radiation in the sam-
ples more sensitive to heating. The effects of heating
in such samples were observed in the spectra as a
broad band of black-body radiation in the wavenum-
ber region above 2500 cm−1. Reference spectra of
pure chemical compounds (Sigma Aldrich) typically
constituting urinary sediments were recorded for
the qualitative evaluation of the spectra allowing us
to identify all constituents in the analysed deposits
with high chemical sensitivity. Spectral analysis was
performed on raw spectra with no pre-processing
procedures applied. Optical images of the urinary
crystals were recorded using the visible mode of
the same instrument, which includes a visible light
source and a CCD camera for this purpose.
For the FTIR studies, the urinary stones were
ground with an agate mortar, mixed with IR-
transparent KBr powder (ratio 1:100) and pressed
into a pellet using a hydraulic press. The KBr pellets
were analysed with a Vertex 70 IR spectrometer
(Bruker Optik GmbH, Ettlingen, Germany) equipped
with a liquid nitrogen cool mercury cadmium tel-
luride (MCT) detector. The spectra were recorded
with 4 cm−1spectral resolution. One hundred
twenty-eight (128) interferograms were obtained,
averaged, and converted into a resulting spectrum
using the three-term Blackman–Harris apodization
function and a zero-filling factor of 2. The spectra
were analysed by comparing them with pure chem-
ical component reference spectra recorded in the
same way.
3. Results
The chemical composition of the urinary sediments
of fifteen patients suffering from urolithiasis was
C. R. Chimie — Online first, 28th September 2021
4Sandra Tamosaityte et al.
investigated by means of Raman spectroscopy. The
characteristic Raman spectra and optical images of
the sediments are shown in Figures 1–4. In the spec-
tra that are presented in the figures, the spectral re-
gion varies depending on the valuable spectral infor-
mation of interest. The most characteristic spectral
bands are also indicated in the spectra. Although the
samples in some cases also contained cells, all the
analysed deposits yielded clear signal of the consti-
tuting minerals. This could be explained by the fact
that the Raman scattering cross-section of minerals is
typically much higher while also predominantly con-
taining spectral bands in lower wavenumber region
compared to organic compounds constituting cells.
Analysis of the Raman spectra of urinary sedi-
ments confirmed that the main urinary stone form-
ing materials were present at elevated concentra-
tions in the urine of patients with urolithiasis: (i) cal-
cium oxalate monohydrate CaC2O4·H2O (n=5,
33%); (ii) urates: uric acid C5H4N4O3, uric acid dihy-
drate C5H4N4O3·2H2O, and ammonium acid urate
C5H7N5O3(n=4, 27%); (iii) brushite CaHPO4·2H2O
(n=4, 27%); (iv) struvite (NH4)MgPO4·6H2O (n=1,
7%). Those were single-component sediments. One
of the urinary deposits was composed of three differ-
ent components: calcium oxalate monohydrate, hy-
droxyapatite, and calcite. We did not find crystals of
calcium oxalate dehydrate nor the rare compounds,
such as N-acetylsulfametoxazole or other drugs, in
any of the analysed sediments. Since Raman spectra
of sediment constituting materials are distinct, this
likely due to the small size of the sample set limited
by the duration of the project and the low prevalence
of acute neprolithiasis patients in Lithuania, and not
due to limitations of the technique.
Table 1 summarizes the 15 cases of the chem-
ical composition of urinary sediments and chem-
ical composition of urinary stones from the same
patients. At least one molecular compound was the
same among samples coming from the same pa-
tient. However, oxalate stones were always accom-
panied by phosphatic additives, amorphous phos-
phates and hydroxyapatite being the most common.
The phosphates were not found in corresponding
urinary sediments. Instead, brushite and struvite
were found in five urinary sediment samples. Par-
ticularly in the case of brushite sediments, low cor-
relation was observed with the composition of cor-
responding urinary stones, which were constituted
from amorphous phosphates, hydroxyapatite and
calcium oxalate instead. Different urates were found
in the urinary sediments, but the urinary stones of
all those patients were composed of uric acid anhy-
drous. In this case, we still consider that the chemical
composition of urinary deposits correlates since uric
acid dihydrate and ammonium acid urate are less
stable forms of urates and can recrystallize into uric
acid anhydrous under decrease in urine pH [36,37].
4. Discussion
Urine saturation with some specific chemical
elements—usually oxalates, phosphates, ammo-
nium ions, and magnesium—is a primary and re-
quired factor for increased risk of urinary stone for-
mation [38]. Nevertheless, initial crystallisation re-
sulting in 10–12 µm single urinary crystals does not
necessarily lead to the formation of a urinary stones
and is common for healthy people [39,40]. Precipi-
tation of significant amounts of crystals and/or suit-
able conditions in the urinary tract is, however, very
likely to lead to the aggregation of small crystals typ-
ically bound by a protein matrix. Such sediments,
which are made of small crystals or are mixed with
an organic matrix, are larger and usually have an
obscure morphology [40]. In addition, some aggre-
gates can consist of several chemical compounds.
Urinary stone formation is much more frequent in
patients with larger size crystals and aggregates in
their urine [41]. Particular attention should be paid
when investigating the chemical composition of such
larger crystals and aggregates. Here we used a FT–
Raman spectrometer that allowed us analysing uri-
nary crystals and aggregates approximately 100 µm
in size. However, even smaller sediments as small
as 1 µm could and should in the future be analysed
using the method by employing objectives of higher
magnification and numerical aperture for tighter
focusing of laser radiation.
Optical microscopy, which is nowadays used in
laboratory medicine, is unable to recognize large sin-
gle or multi-chemical aggregates because of their un-
usual morphology [10,13,41]. The crystals having the
most clinical significance are often left unidentified
or incorrectly identified during routine urinalysis.
FT–Raman spectroscopy proved to be a suitable
method to determine the exact molecular com-
pounds of urinary sediments independent of their
C. R. Chimie — Online first, 28th September 2021
Sandra Tamosaityte et al. 5
Table 1. Presence of chemical components in urinary sediments and urinary stones among 15 patients
suffering from urinary stone disease
Chemical composition
of urinary sediments
Chemical composition of urinary stones Number
of cases
Calcium oxalate monohydrate Calcium oxalate monohydrate +amorphous phosphates 3
Calcium oxalate monohydrate Calcium oxalate monohydrate +hydroxyapatite 2
Uric acid anhydrous Uric acid anhydrous 1
Uric acid dihydrate Uric acid anhydrous 2
Ammonium acid urate Uric acid anhydrous 1
Brushite Calcium oxalate monohydrate +amorphous phosphates 3
Brushite Calcium oxalate monohydrate +hydroxyapatite 1
Struvite Struvite 1
Calcium oxalate monohydrate +
calcite +hydroxyapatite
Struvite +hydroxyapatite +calcium oxalate monohydrate 1
morphology. Figures 1 and 2 illustrate cases when
both typical and atypical crystals of brushite and
struvite were found in samples. Brushite tends to
form crystals shaped as long prisms with one sharp
end and combine into spiky star-like formations as
shown in the upper image of Figure 1. The bottom
image, however, reveals morphologically indescrib-
able sediment. Raman spectra were found to be the
same for both and the sediments were identified as
brushite. A very similar situation was encountered
for atypical sediments and sediments having a de-
fined morphology, both corresponding to struvite
when investigated by means of Raman scattering
spectroscopy.
It turned out to be challenging to record Ra-
man spectrum of high quality in terms of signal-
to-noise ratio for deposits of calcium oxalate, which
were heated when exposed to the laser radiation
and subsequently thermally damaged. The heating
could be caused by a typically brown colour of the
larger calcium oxalate crystals suggesting presence
of pigments or other types of organic contaminants,
which increase the absorption of the laser radia-
tion and makes them more susceptible to heating.
Therefore, the power of the laser had to be low and
the number of spectra averaged had to be increased
substantially to achieve a signal-to-noise ratio suf-
ficient for spectral analysis. This in turn increased
the time required for the experiment. Importantly,
Raman spectroscopy allows one to distinguish dif-
ferent hydrates of calcium oxalate, which can be
indicative of the different aetiology of the urinary
stone and provide important information for sub-
sequent treatment [20]. The most intense spectral
bands of calcium oxalate monohydrate are a doublet
at 1490 cm−1and 1463 cm−1assigned to symmetrical
νs(COO−) stretch vibrations. On the other hand, cal-
cium oxalate dihydrate yields only one spectral band
in this spectral region near 1477 cm−1[16]. The Ra-
man spectrum in Figure 3 clearly shows the urinary
sediment to be calcium oxalate monohydrate. It is
not possible to obtain such information from the op-
tical image, since the large, likely aggregated deposit
does not appear in the typical shape of calcium ox-
alate crystals.
Raman spectra are also useful for distinguishing
various types of urates. Uric acid anhydrous and uric
acid dihydrate are the most common urates consti-
tuting urinary stones and urinary sediments. Uric
acid monohydrate is also reported as a possible con-
stituent [42]. Of note, both hydrates are rarely found
in urinary stones, with the hydration possibly lost
during stone growth. We have, however, discerned
the presence of uric acid dihydrate in urinary de-
posits. An example of the atypical morphological
structure of a uric acid dihydrate urinary deposit is
shown in Figure 4 together with the Raman spec-
trum of the deposit. Uric acid anhydrous and ammo-
nium acid urate were also identified as constituents
of urinary sediments in this work. The varying inten-
sities and Raman shifts of the spectral bands related
to the in-plane bending motions of purine rings can
be used as spectral markers for recognition of various
urates.
C. R. Chimie — Online first, 28th September 2021
6Sandra Tamosaityte et al.
Figure 1. FT–Raman spectrum of brushite urinary sediments (laser power: 180 mW, number of averaged
spectra: 2000) (left) and optical images of typical (top) and atypical (bottom) urinary deposits composed
of brushite.
Figure 2. FT–Raman spectrum of struvite urinary sediments (laser power: 180 mW, number of averaged
spectra: 2000) (left) and optical images of typical (top) and atypical (bottom) urinary deposits composed
of struvite.
FT–Raman scattering spectroscopy proved to be
a reliable method to determine the chemical com-
position of multi-component urinary sediments. As
can be seen from the optical image of the urinary
deposit in Figure 5, it has irregular morphology and
no crystal structure, which makes it very difficult
C. R. Chimie — Online first, 28th September 2021
Sandra Tamosaityte et al. 7
Figure 3. FT–Raman spectrum (laser power: 9 mW, number of averaged spectra: 170,000) (left) and
optical image (right) of calcium oxalate monohydrate urinary sediment.
Figure 4. FT–Raman spectrum (laser power: 80 mW, number of averaged spectra: 20,000) (left) and
optical image (right) of uric acid urinary sediment.
to determine its chemical composition. On the
contrary, the Raman spectrum of this deposit in-
dicates the three different chemical compounds:
calcium oxalate monohydrate, hydroxyapatite, and
calcite. The most intensive spectral band, which is
at 1085 cm−1and is characteristic of the vibrations
of the CO2−
3group, and the one at 280 cm−1repre-
sent CaCO3(calcite) in the sample [43]. A spectral
band at 960 cm−1characteristic of hydroxyapatite
can also be observed. All other spectral bands in the
Raman spectrum of this urinary deposit are assigned
to calcium oxalate monohydrate.
The close similarity of the chemical composi-
tion of urinary sediments of patients with the same
C. R. Chimie — Online first, 28th September 2021
8Sandra Tamosaityte et al.
Figure 5. Optical image of urinary deposit (top left corner), Raman spectra of the deposit (bottom),
and reference chemical compounds indicating calcium oxalate monohydrate, calcite, and hydroxyapatite
Raman spectra.
urinary stone disease indicates that saturation of
urine with specific chemical elements can result in
urinary stone formation. For patients in the risk
group, such as those with increased possibility of re-
currence or with a family history of urinary stones,
the exact evaluation of the chemical components in
urinary sediments could be crucial for prevention
purposes.
The differences between the chemical composi-
tion of urinary sediments and urinary stones can also
provide valuable information concerning the pro-
cesses of urinary stone formation. In our study, uric
acid urinary stones were composed of uric acid anhy-
drous, but the urinary deposits of the same patients
were also found to be uric acid dihydrate or ammo-
nium acid urate. This suggests the occurrence of de-
hydration and ion separation processes at the time of
stone formation.
The most significant differences were found in the
patients having urinary sediments of brushite and
stones having a mixture of calcium oxalate monohy-
drate with amorphous phosphates or with hydrox-
yapatite. Brushite and amorphous phosphates, as
well as calcium oxalate, are formed in high calcium
concentrations. Hydroxyapatite can occur via phase
transformation from brushite [44]. Thus, the exis-
tence of brushite in urine can suggest the exis-
tence of hypercalciuria and formation of calcium
oxalate-phosphate stones. On the other hand, as a
constituent in multicomponent urinary stones, pure
brushite occurrence varies from less than 1% to
about 20% according to various authors [12,45], and
in general it is considered a rare component [16]. For
single component calcium oxalate stones, only cal-
cium oxalate urinary sediments were found.
In this work we provide pilot evidence for the cor-
relation between the chemical composition of uri-
nary sediments and stones, but more patients need
to be included in the study for the results to be statis-
tically reliable. We show that FT–Raman spectroscopy
is suitable for reliably identifying urinary deposits
larger than 100 µm in size with no significant influ-
ence of fluorescence as observed in previous stud-
ies [31,33]. The long spectral acquisition time is the
main limiting factor for the method to be used in a
routine way in clinical practice. This can be alleviated
in the future by using high magnification and numer-
ical aperture objectives (which would also result in
C. R. Chimie — Online first, 28th September 2021
Sandra Tamosaityte et al. 9
ability to analyse samples as small as 1 µm) or apply-
ing mathematical noise reduction procedures for low
signal-to-noise spectra [46–48].
Urinary stones are usually diagnosed in an already
late stage of their formation, e.g., only when the pa-
tient starts feeling pain. Regular tests of urinary sed-
iments to determine its exact chemical composition
could be key to early prevention of urinary stone dis-
ease. In this work, Raman spectroscopy proved to be
informative for the chemical identification of both
typical and atypical urinary crystals and crystal clus-
ters. Although this is a pilot study and more patient
cases need to be investigated for the results to be
statistically reliable, spectral analysis of the deposits
could help in prescribing the appropriate preventive
measures, such as diet and lifestyle changes, for peo-
ple at risk of urinary stones. In addition, distinguish-
ing chemical compounds of even the smallest chem-
ical differences can be of high value in determining
the causes and conditions of the initial formation and
growth processes of urinary stones.
5. Conclusions
FT–Raman spectroscopy is an effective and very sen-
sitive method to determine the chemical composi-
tion of urinary sediments no matter their morpho-
logical structure and is especially useful for the inves-
tigation of unusual crystals and amorphous clusters,
which cannot be identified by optical microscopy
widely used in standard medical practice. Use of
1064 nm NIR laser for excitation of Raman scatter-
ing ensures suppression of fluorescence background
common in biological samples. In contrast to optical
microscopy, the method does not rely on the skills of
laboratory personnel since the Raman spectra pro-
vides direct chemical information at molecular level.
We found correlation between the chemical compo-
sition of urinary stones and urinary sediments, which
suggests that the examination of the sediments by
FT–Raman spectroscopy can be considered a relevant
approach for early diagnosis of urinary stone forma-
tion and determination of appropriate action to pre-
vent this process.
References
[1] Y. Liu, Y. Chen, B. Liao, D. Luo, K. Wang, H. Li, G. Zeng, Asian J.
Urol., 2018, 5, 205-214.
[2] I. Sorokin, C. Mamoulakis, K. Miyazawa, A. Rodgers, J. Talati,
Y. Lotan, World J. Urol., 2017, 35, 1301-1320.
[3] O. A. Raheem, Y. S. Khandwala, R. L. Sur, K. R. Ghani, J. D.
Denstedt, Eur. Urol. Focus, 2017, 3, 18-26.
[4] S. R. Khan, M. S. Pearle, W. G. Robertson, G. Gambaro, B. K.
Canales, S. Doizi, O. Traxer, H.-G. Tiselius, Nat. Rev. Dis.
Primers, 2016, 2, 1-23.
[5] T. Alelign, B. Petros, Adv. Urol., 2018, 2018, article
no. e3068365.
[6] V. Frochot, M. Daudon, Int. J. Surg., 2016, 36, 624-632.
[7] C. Martins Maria, A. Meyers Anthony, A. Whalley Natalie,
L. Rodgers Allen, J. Urol., 2002, 167, 317-321.
[8] S. R. Khan, P. A. Glenton, Brit. J. Urol., 1996, 77, 506-511.
[9] G. B. Fogazzi, Nephrol. Dial. Transplant., 1996, 11, 379-387.
[10] C. Cavanaugh, M. A. Perazella, Am. J. Kidney Dis., 2019, 73,
258-272.
[11] M. Daudon, V. Frochot, Clin. Chem. Lab. Med. (CCLM), 2015,
53, s1479-s1487.
[12] L. Estepa, M. Daudon, Biospectroscopy, 1997, 3, 347-369.
[13] M. E. Baños-Laredo, C. A. Núñez-Álvarez, J. Cabiedes Reuma-
tol. Clín. (Engl. Ed.), 2010, 6, 268-272.
[14] M. Pucetaite, V. Hendrixson, A. Zelvys, F. Jankevicius, R. Tyla,
J. Ceponkus, V. Sablinskas, J. Mol. Struct., 2013, 1031, 38-42.
[15] M. Pucetaite, S. Tamosaityte, R. Galli, V. Sablinskas, G. Steiner,
J. Raman Spectrosc., 2017, 48, 22-29.
[16] P. Carmona, J. Bellanato, E. Escolar, Biospectroscopy, 1997, 3,
331-346.
[17] A. H. Khan, S. Imran, J. Talati, L. Jafri, Investig. Clin. Urol.,
2018, 59, 32-37.
[18] X. Cui, Z. Zhao, G. Zhang, S. Chen, Y. Zhao, J. Lu, Biomed. Opt.
Express, 2018, 9, 4175-4183.
[19] V. K. Singh, P. K. Rai, Biophys. Rev., 2014, 6, 291-310.
[20] M. Daudon, A. Dessombz, V. Frochot, E. Letavernier, J.-P. Hay-
mann, P. Jungers, D. Bazin, C. R. Chim., 2016, 19, 1470-1491.
[21] P. A. Bhatt, P. Paul, J. Chem. Sci., 2008, 120, 267-273.
[22] Y. M. Fazil Marickar, P. R. Lekshmi, L. Varma, P. Koshy, Urol.
Res., 2009, 37, 271-276.
[23] Y. M. Fazil Marickar, P. R. Lekshmi, L. Varma, P. Koshy, Urol.
Res., 2009, 37, 277-282.
[24] S. Tamosaityte, E. Baltakyte, D. Blazevic, M. Pucetaite, J. Ce-
ponkus, V. Hendrixson, S. Varvuolyte, V. Sablinskas, in Proc. of
SPIE, vol. 8798, SPIE, 2013.
[25] M. Daudon, M. F. Protat, R. J. Reveillaud, H. Jaeschke-Boyer,
Kidney Int., 1983, 23, 842-850.
[26] V. Castiglione, P.-Y. Sacré, E. Cavalier, P. Hubert, R. Gadisseur,
E. Ziemons, PLoS ONE, 2018, 13, article no. e0201460.
[27] A. Kudelski, Talanta, 2008, 76, 1-8.
[28] J. A. T. Poloni, M. A. Perazella, E. Keitel, C. A. Marroni, S. B.
Leite, L. N. Rotta, CN, 2019, 92, 141-150.
[29] J. Berüter, J.-P. Colombo, U. P. Schlunegger, Eur. J. Biochem.,
1975, 56, 239-244.
[30] C. Krafft, Anal. Bioanal. Chem., 2004, 378, 60-62.
[31] Z.-T. Chen, C.-H. Wang, H. K. Chiang, in Proc. of SPIE, vol.
11359, SPIE, 2020.
[32] V. Frochot, V. Castiglione, I. T. Lucas, J.-P. Haymann, E. Letav-
ernier, D. Bazin, G. B. Fogazzi, M. Daudon, Clin. Chim. Acta,
2021, 515, 1-4.
[33] P.-A. Lo, Y.-H. Huang, Y.-C. Chiu, L.-C. Huang, J.-L. Bai, S.-H.
C. R. Chimie — Online first, 28th September 2021
10 Sandra Tamosaityte et al.
Wu, C.-C. Huang, H. K. Chiang, J. Raman Spectrosc., 2019, 50,
34-40.
[34] C.-H. Wang, J.-X. Zeng, P.-C. Chen, H.-H. K. Chiang, in Fu-
ture Trends in Biomedical and Health Informatics and Cyber-
security in Medical Devices (K.-P. Lin, R. Magjarevic, P. de Car-
valho, eds.), Springer International Publishing, Cham, 2020,
122-128.
[35] L. Cui, H. J. Butler, P. L. Martin-Hirsch, F. L. Martin, Anal.
Methods, 2016, 8, 481-487.
[36] M. Cameron, N. M. Maalouf, J. Poindexter, B. Adams-Huet,
K. Sakhaee, O. W. Moe, Kidney Int., 2012, 81, 1123-1130.
[37] Z. Wang, L. Königsberger, E. Königsberger, Monatsh Chem.,
2018, 149, 327-332.
[38] A. P. Evan, Pediatr. Nephrol., 2010, 25, 831-841.
[39] M. Daudon, C. Hennequin, G. Boujelben, B. Lacour,
P. Jungers, Kidney Int., 2005, 67, 1934-1943.
[40] B.-S. Gui, R. Xie, X.-Q. Yao, M.-R. Li, J.-M. Ouyang, Bioinorg.
Chem. Appl., 2009, 2009, article no. e925297.
[41] Y. M. Fazil Marickar, A. Salim, Urol. Res., 2009, 37, 359-368.
[42] G. Schubert, G. Reck,H. Jancke, W. Kraus,C. Patzelt, Urol. Res.,
2005, 33, 231-238.
[43] J. Urmos, S. K. Sharma, F. T. Mackenzie, Am. Mineral., 1991,
76, 641-646.
[44] A. Hesse, D. Heimbach, World J. Urol., 1999, 17, 308-315.
[45] L. Benramdane, M. Bouatia, M. O. B. Idrissi, M. Draoui, Spec-
trosc. Lett., 2008, 41, 72-80.
[46] S. J. Barton, T. E. Ward, B. M. Hennelly, Anal. Methods, 2018,
10, 3759-3769.
[47] H. Chen, W. Xu, N. Broderick, J. Han, J. Raman Spectrosc.,
2018, 49, 1529-1539.
[48] X. Y. Zhao, G. Y. Liu, Y. T. Sui, M. Xu, L. Tong, Spectrochim.
Acta A: Mol. Biomol. Spectrosc., 2021, 250, article no. 119374.
C. R. Chimie — Online first, 28th September 2021
