Direct identification and quantitation of fluorescent whitening agent in wheat flour based on multi-molecular infrared (MM-IR) spectroscopy and stereomicroscopy.

Fluorescent brighteners, illegally used to whitening wheat flour, are detrimental to people health. The aim was to establish a rapid and direct method to identify and quantify fluorescent whitening agent OB-1 (FWA OB-1) in wheat flour by using multi-molecular infrared (MM-IR) spectroscopy combined with stereomicroscopy. Characteristic peak profile of FWA OB-1 used as a judgment basis was spatially revealed by stereomicroscopy with group-peak matching of MM-IR at 1614 cm-1, 1501 cm-1 and 893 cm-1 and were further unveiled by the second derivative infrared spectroscopy (SD-IR) and its two-dimensional correlation infrared (SD-2DCOS IR) spectroscopy for higher resolution, and were validated by high-performance liquid chromatography (HPLC). Moreover, a quantitative prediction model based on IR spectra was established by partial least squares 1 (PLS1) (R2, 98.361; SEE, 5.032; SEP, 5.581). The developed method was applicable for rapid and direct analysis of FWA OB-1 (low to 10 ppm) in flour with relative standard deviation (RSD) of 5%. The capabilities of MM-IR with spectral qualitative and quantitative analysis would be applicable to direct identification and quantitation of fluorescent whitening agents or other IR-active compounds in powder objects.

Analysis of protein structure changes and quality regulation of surimi during gelation based on infrared spectroscopy and microscopic imaging.

A developed Fourier transform infrared spectroscopy (FT-IR) was employed to investigate changes of protein conformation, which played significant roles in maintaining stable protein networks of white croaker surimi gel, exploring the relationship between protein conformation and surimi gel networks. Spectra of surimi and gels with different grades (A, AA, FA and SA) were analyzed by tri-step FT-IR method and peak-fitting of deconvolved and baseline corrected amide I bands (1600~1700 cm-1). The result showed that α-helix was the main conformation of surimi proteins. During surimi gelation, α-helix of myosin partially transformed into ß-sheet, ß-turn and random coil structures. ß-sheet and random coil structures were the main protein conformations maintaining the structure of surimi gel, of which ß-sheet made the main contribution to gel strength. Scanning electron microscopy (SEM) result revealed that surimi gels had a fibrous and homogeneous network structure. Moreover, ordered interconnections between three-dimensional proteins networks of gels were inclined to emerge in higher grade surimi, in agreement with the gel strength results. It was demonstrated that the tri-step FT-IR spectroscopy combined with peak-fitting could be applicable for exploration of surimi protein conformation changes during gelation to deepen understanding of its effect on gel quality.

A rapid analytical and quantitative evaluation of formaldehyde in squid based on Tri-step IR and partial least squares (PLS).

Formaldehyde abuse for retaining squid freshness is detrimental to public health. The aim is to establish a rapid and quantitative detection method of formaldehyde in squid for screening massive samples. A linear relationship between formaldehyde concentration in squid and formaldehyde concentration in squid soaked water was observed using HPLC. Chemical profile variances of squids were rapidly analyzed by Tri-step infrared spectroscopy. Specifically, with increasing formaldehyde concentration, peak intensities of 2927cm-1 (vas(CH2)), 1081cm-1 (glycogen), 1631cm-1 (ß-sheet proteins) decreased while 1655cm-1 (α-helix proteins) increased. Spectral curve-fitting results further disclosed that ß-sheet proteins were transformed to α-helix and ß-turn conformations. Furthermore, a quantitative prediction model based on IR spectra was established by PLS (R2, 0.9787; RMSEC, 5.51). The developed method was applicable for rapid (c.a. 5min) and quantitative analysis of formaldehyde in squids with LOD of 15mg/kg.

Chemical profiling and adulteration screening of Aquilariae Lignum Resinatum by Fourier transform infrared (FT-IR) spectroscopy and two-dimensional correlation infrared (2D-IR) spectroscopy.

As a kind of expensive perfume and valuable herb, Aquilariae Lignum Resinatum (ALR) is often adulterated for economic motivations. In this research, Fourier transform infrared (FT-IR) spectroscopy is employed to establish a simple and quick method for the adulteration screening of ALR. First, the principal chemical constituents of ALR are characterized by FT-IR spectroscopy at room temperature and two-dimensional correlation infrared (2D-IR) spectroscopy with thermal perturbation. Besides the common cellulose and lignin compounds, a certain amount of resin is the characteristic constituent of ALR. Synchronous and asynchronous 2D-IR spectra indicate that the resin (an unstable secondary metabolite) is more sensitive than cellulose and lignin (stable structural constituents) to the thermal perturbation. Using a certified ALR sample as the reference, the infrared spectral correlation threshold is determined by 30 authentic samples and 6 adulterated samples. The spectral correlation coefficient of an authentic ALR sample to the standard reference should be not less than 0.9886 (p=0.01). Three commercial adulterated ALR samples are identified by the correlation threshold. Further interpretation of the infrared spectra of the adulterated samples indicates the common adulterating methods - counterfeiting with other kind of wood, adding ingredient such as sand to increase the weight, and adding the cheap resin such as rosin to increase the content of resin compounds. Results of this research prove that FT-IR spectroscopy can be used as a simple and accurate quality control method of ALR.

Chemical morphology of Areca nut characterized directly by Fourier transform near-infrared and mid-infrared microspectroscopic imaging in reflection modes.

Fourier transform near-infrared (NIR) and mid-infrared (MIR) imaging techniques are essential tools to characterize the chemical morphology of plant. The transmission imaging mode is mostly used to obtain easy-to-interpret spectra with high signal-to-noise ratio. However, the native chemical compositions and physical structures of plant samples may be altered when they are microtomed for the transmission tests. For the direct characterization of thick plant samples, the combination of the reflection NIR imaging and the attenuated total reflection (ATR) MIR imaging is proposed in this research. First, the reflection NIR imaging method can explore the whole sample quickly to find out typical regions in small sizes. Next, each small typical region can be measured by the ATR-MIR imaging method to reveal the molecular structures and spatial distributions of compounds of interest. As an example, the chemical morphology of Areca nut section is characterized directly by the above approach.

Direct and simultaneous detection of organic and inorganic ingredients in herbal powder preparations by Fourier transform infrared microspectroscopic imaging.

Herbal powder preparation is a kind of widely-used herbal product in the form of powder mixture of herbal ingredients. Identification of herbal ingredients is the first and foremost step in assuring the quality, safety and efficacy of herbal powder preparations. In this research, Fourier transform infrared (FT-IR) microspectroscopic identification method is proposed for the direct and simultaneous recognition of multiple organic and inorganic ingredients in herbal powder preparations. First, the reference spectrum of characteristic particles of each herbal ingredient is assigned according to FT-IR results and other available information. Next, a statistical correlation threshold is determined as the lower limit of correlation coefficients between the reference spectrum and a larger number of calibration characteristic particles. After validation, the reference spectrum and correlation threshold can be used to identify herbal ingredient in mixture preparations. A herbal ingredient is supposed to be present if correlation coefficients between the reference spectrum and some sample particles are above the threshold. Using this method, all kinds of herbal materials in powder preparation Kouqiang Kuiyang San are identified successfully. This research shows the potential of FT-IR microspectroscopic identification method for the accurate and quick identification of ingredients in herbal powder preparations.

[Analysis and Identification of H. rhamnoides subsp. sinensis Harvested From Different Producing Areas by FTIR Spectroscopy].

The accurate identification of traditional Chinese medicine (TCM) which collected from different producing areas is important for its quality control and clinical effects. In the present study, Fourier transform infrared spectroscopy (FTIR) combined with second derivative spectra were used to identify and analyze H. rhamnoides subsp. sinensis from different producing areas. The characteristic absorption peaks, including 2 925, 2 854, 1 743, 1 541 and 1 173 cm-1 belonging to fatty acids, flavonoids and saccharides appear in all 20 samples. But the absorption peak intensities and locations varied due to the different geographical regions. The results also showed that the absorption peaks at the range of 3 429～3 336 and 1 744 cm-1 were important characteristic absorption peaks which can identify H. rhamnoides subsp. sinensis from different producing areas. Also, absorption peaks at 1 030 and 1 516 cm-1 further confirmed the existence of flavonoids in all samples by comparing the second derivative infrared spectra in the range of 1 800～1 000 cm-1. However, the samples' differences can be intuitively found around peaks 1 711, 1 476 cm-1 and ranges from 1 689～1 515 and 1 400～1 175 cm-1. The results demonstrated that FTIR was a simple, convenient, fast and intuitive approach to identify and analyze H. rhamnoides subsp. sinensis from different producing areas. This method provides foundations for the analysis of chemical compositions and quality control for the TCM.

[TOF-SIMS Study of Mannitol and Cordycepin in Cordyceps Sinensis].

Cordyceps sinensis is a well-known traditional Chinese medicine; it is also called DongChongXiaCao (winter worm summer grass) in Chinese. Mannitol and cordycepin, the most important two pharmacological active components of cordyceps sinensis, were studied with TOF-SIMS. This Study was focused on the chemical information including 251 amu mass peak. Based on high mass resolution of TOF-SIMS analysis, the fragment ions of 251 and 252 amu detected in Cordyceps sinensis may not be the molecular ion M+ and/or[M+H]+ of cordycepin, which ispossiblely the root cause of the argument in the study of cordycepin in published papers .It could be a basis for further study of cordycepin components of cordyceps sinensis in the future. The 181amu mass peak of minus ion in mannitol was also studied in detail and was certified to be a reliable evidence of mannitol. This research shows that TOF-SIMS has been proven as an effective method in the study of cordyceps sinensis.

[Development of FTIR fingerprint for identification of armand clematis stem (Chuanmutong) and related herbs].

Armand clematis stem (Clematidis Armandii Caulis, Chuanmutong) is a widely used Chinese herb to disinhibit urine and relieve stranguria. It is difficult to be identified owing to its various macroscopic feature and unknown characteristic compounds. Thus, total of 24 Chuanmutong samples and 7 related herbs including four manshurian aristolochia stem (Aristolochiae Manshuriensis Caulis, Guanmutong) and three akebia stem (Akebiae Caulis, Mutong) samples were collected and analyzed in the range of 4 000 - 400 cm⁻¹ by Fourier Transform Infrared (FTIR) and two-dimensional infrared correlation spectroscopy (2D-FTIR) techniques. The FTIR spectra of 24 Chuanmutong samples are consistent in the spectrum profiles, position and intensity of characteristic peaks. 20 of the 24 Chuanmutong samples were randomly selected as calibration samples to calculate and simulate mean spectrum. This mean spectrum is named as FTIR fingerprint of Chuanmutong with characteristic peaks at 3 412, 2 932, 1 739, 1 639, 1 509, 1 456, 1 426, 1 376, 1 332, 1 261, 1 159, 1 035, 897 ,609 cm⁻¹. Meanwhile, the limited level (Mean-3σ=0.992 6) to identify true or false Chuanmutong by correlation coefficient of FTIR spectra was calculated based on the 20 Chuanmutong calibration samples. Then, the rest 4 Chuanmutong, 4 Guanmutong and 3 Mutong samples were used as validation samples to evaluate the identification efficacy. The result shows that the FTIR spectra of 4 Chuanmutong validation samples were similar to the fingerprint. Their correlation coefficients of FTIR spectra were over the limited level and accepted as Chuanmutong. However, the spectra of Guanmutong and Mutong were significantly different from Chuanmutong fingerprint. The correlation coefficients of Guanmutong (0.902 1-0.940 4, n=4) and Mutong (0.954 9-0.978 9, n=3) FTIR spectra were less than the limited level and rejected from Chuanmutong. Furthermore, the number, position and intensity of auto-peaks on the 2D-FTIR were drastically different among the three herbs. It is concluded that the developed FTIR fingerprinting can be rapidly and accurately identify Chuanmutong and differentiate from related herbs.

Rapid determination and chemical change tracking of benzoyl peroxide in wheat flour by multi-step IR macro-fingerprinting.

BPO is often added to wheat flour as flour improver, but its excessive use and edibility are receiving increasing concern. A multi-step IR macro-fingerprinting was employed to identify BPO in wheat flour and unveil its changes during storage. BPO contained in wheat flour (<3.0 mg/kg) was difficult to be identified by infrared spectra with correlation coefficients between wheat flour and wheat flour samples contained BPO all close to 0.98. By applying second derivative spectroscopy, obvious differences among wheat flour and wheat flour contained BPO before and after storage in the range of 1500-1400 cm(-1) were disclosed. The peak of 1450 cm(-1) which belonged to BPO was blue shifted to 1453 cm(-1) (1455) which belonged to benzoic acid after one week of storage, indicating that BPO changed into benzoic acid after storage. Moreover, when using two-dimensional correlation infrared spectroscopy (2DCOS-IR) to track changes of BPO in wheat flour (0.05 mg/g) within one week, intensities of auto-peaks at 1781 cm(-1) and 669 cm(-1) which belonged to BPO and benzoic acid, respectively, were changing inversely, indicating that BPO was decomposed into benzoic acid. Moreover, another autopeak at 1767 cm(-1) which does not belong to benzoic acid was also rising simultaneously. By heating perturbation treatment of BPO in wheat flour based on 2DCOS-IR and spectral subtraction analysis, it was found that BPO in wheat flour not only decomposed into benzoic acid and benzoate, but also produced other deleterious substances, e.g., benzene. This study offers a promising method with minimum pretreatment and time-saving to identify BPO in wheat flour and its chemical products during storage in a holistic manner.

Rapid discrimination of three marine fish surimi by Tri-step infrared spectroscopy combined with Principle Component Regression.

A Tri-step infrared spectroscopy (Fourier transform infrared spectroscopy (FT-IR) integrated with second derivative infrared (SD-IR) spectroscopy and two-dimensional correlation infrared spectroscopy (2DCOS-IR)) combined with Principal Component Regression (PCR) were employed to characterize and discriminate three marine fish surimi (white croaker surimi (WCS), hairtail surimi (HS) and red coat surimi (RCS)). The three surimi had similar IR macro-fingerprints (similarity>0.7) especially for the absorption bands of amide groups. Compared to the other two surimi, however, RCS had a middle strong characteristic peak of lipids at 1745 cm(-1), indicating that RCS had the highest content of lipids. SD-IR spectra of the three surimi enhanced the spectral resolution and amplified the small differences, especially at about 1682 cm(-1), 1679 cm(-1), 1656 cm(-1) and 1631 cm(-1), suggesting that the three had different profiles of proteins. Moreover, evident differences were observed in 2DCOS-IR spectra of 1500-1800 cm(-1). WCS had one strong (1620 cm(-1)) and three weak auto-peaks (1520 cm(-1), 1552 cm(-1), 1706 cm(-1)). HS had three strong (1621 cm(-1), 1648 cm(-1), 1708 cm(-1)) and two weak auto-peaks (1523 cm(-1), 1553 cm(-1)), whereas RCS had one strong (1623 cm(-1)) and three weak auto-peaks (1525 cm(-1), 1709 cm(-1), 1738 cm(-1)). Furthermore, sixty batches of surimi (twenty for each surimi) were objectively classified by PCR. It was demonstrated that the Tri-step infrared spectroscopy combined with PCR could be applicable for discrimination of precious marine fish surimi in a direct, rapid and holistic manner.

Data-driven signal-resolving approaches of infrared spectra to explore the macroscopic and microscopic spatial distribution of organic and inorganic compounds in plant.

The nondestructive and label-free infrared (IR) spectroscopy is a direct tool to characterize the spatial distribution of organic and inorganic compounds in plant. Since plant samples are usually complex mixtures, signal-resolving methods are necessary to find the spectral features of compounds of interest in the signal-overlapped IR spectra. In this research, two approaches using existing data-driven signal-resolving methods are proposed to interpret the IR spectra of plant samples. If the number of spectra is small, "tri-step identification" can enhance the spectral resolution to separate and identify the overlapped bands. First, the envelope bands of the original spectrum are interpreted according to the spectra-structure correlations. Then the spectrum is differentiated to resolve the underlying peaks in each envelope band. Finally, two-dimensional correlation spectroscopy is used to enhance the spectral resolution further. For a large number of spectra, "tri-step decomposition" can resolve the spectra by multivariate methods to obtain the structural and semi-quantitative information about the chemical components. Principal component analysis is used first to explore the existing signal types without any prior knowledge. Then the spectra are decomposed by self-modeling curve resolution methods to estimate the spectra and contents of significant chemical components. At last, targeted methods such as partial least squares target can explore the content profiles of specific components sensitively. As an example, the macroscopic and microscopic distribution of eugenol and calcium oxalate in the bud of clove is studied.

[Tri-Level Infrared Spectroscopic Identification of Hot Melting Reflective Road Marking Paint].

In order to detect the road marking paint from the trace evidence in traffic accident scene, and to differentiate their brands, we use Tri-level infrared spectroscopic identification, which employs the Fourier transform infrared spectroscopy (FTIR), the second derivative infrared spectroscopy(SD-IR), two-dimensional correlation infrared spectroscopy(2D-IR) to identify three different domestic brands of hot melting reflective road marking paints and their raw materials in formula we Selected. The experimental results show that three labels coatings in ATR and FTIR spectrograms are very similar in shape, only have different absorption peak wave numbers, they have wide and strong absorption peaks near 1435 cm⁻¹, and strong absorption peak near 879, 2955, 2919, 2870 cm⁻¹. After enlarging the partial areas of spectrograms and comparing them with each kind of raw material of formula spectrograms, we can distinguish them. In the region 700-970 and 1370-1 660 cm⁻¹ the spectrograms mainly reflect the different relative content of heavy calcium carbonate of three brands of the paints, and that of polyethylene wax (PE wax), ethylene vinyl acetate resin (EVA), dioctyl phthalate (DOP) in the region 2800-2960 cm⁻¹. The SD-IR not only verify the result of the FTIR analysis, but also further expand the microcosmic differences and reflect the different relative content of quartz sand in the 512-799 cm-1 region. Within the scope of the 1351 to 1525 cm⁻¹, 2D-IR have more significant differences in positions and numbers of automatically peaks. Therefore, the Tri-level infrared spectroscopic identification is a fast and effective method to distinguish the hot melting road marking paints with a gradually improvement in apparent resolution.

[Analysis and identification of Semen Glycines Nigrae and Semen Pharbitidis by infrared spectroscopy].

Semen Glycines Nigrae and Semen Pharbitidis containing a large amount of fats and proteins are commonly used in Chinese herbal medicine. Tri-step infrared spectroscopy was applied to fast analyze and identify the two samples. In the conventional infrared spectroscopy, the samples both have obvious characteristic absorption peaks at 1,745 cm(-1) assigned to the stretching mode of C==O in esters. Furthermore, the two kinds of herbs have the peaks at 1,656 and 1,547 cm(-1) assigned to the amide I and II bands of protein. Obviously, the infrared spectra of herbs demonstrate that protein and fat is the major component in two kinds of herbs, and the relative intensity of the peaks assigned to fat and protein indicate their relative content is different. And the result is consistent with the reported. In the second derivative spectra, Semen Pharbitidis has a peak at 1,712 cm(-1) assigned to the organic acid, however, Semen Glycines Nigrae has not this absorption peak. In addition, in the second derivative spectra, appeared more differences between the two samples in shape and intensity of the peaks. In two-dimensional correlation infrared spectra, the two samples were visually distinguished due to their significant differences in auto-peak position and intensity. In the region of 1,500-1,700 cm(-1), Semen Glycines Nigrae has two autopeaks and Semen Pharbitidis has three autopeaks. In the region of 2,800-3,000 cm(-1), the samples both have two autopeaks, but the position of the strongest autopeak is different. It was demonstrated that the Tri-step infrared spectroscopy were successfully applied to fast analyze and identify the two kinds of samples containing the same major component, and made sure the foundation for future researches.

[The analyses and identification of Flos rhododendri mollis and Flos chrysanthemi indici via infrared spectroscopy].

In this study, major chemical components of Flos rhododendri mollis and Flos chrysanthemi indici were characterized using Fourier transform infrared spectroscopy (FTIR). For Flos rhododendri mollis, the bands at 1,648 and 1,543 cm(-1) were attributed to amide I and amide II , respectively, indicating that it contained proteins probably resulting in immunization. In case of Flos chrysanthemi indici, stretching vibration of C==O function group was responsible for the bands at 1,734 and 1,515 cm(-1), as a result of essential oils, lipids, etc. Since FTIR spectra of Flos rhododendri mollis and Flos chrysanthemi indici are almost identical and it is difficult to discriminate them, two-step identification was investigated via secondary derivative of the FTIR spectra. The bands at 1,656 and 1,515 cm(-1) corresponds to flavonoides in Flos rhododendri mollis and Flos chrysanthemi indici. In the secondary derivative of the FTIR spectrum of Flos chrysanthemi indici, characteristic bands of inulin were present at 1,163, 1,077, 1,026, 986 and 869 cm(-1), and therefore Flos chrysanthemi indici contained inulin as well. Tri-step identification was carried out for Flos rhododendri mollis and Flos chrysanthemi indici by means of comparing their 2D-IR correlation spectra in different wave number range. In the characteristic range of flavonoides (1,700-1,400 cm(-1)), Flos rhododendri mollis exhibited 3 obvious autopeaks, while 10 autopeaks were visualized in the 2D-IR correlation spectrum of Flos chrysanthemi indici Moreover, in the characteristic range of glucoside (1,250-900 cm(-1)), 10 and 9 autopeaks were present in the 2D-IR correlation spectra of Flos rhododendri mollis and Flos chrysanthemi indici, respectively. Therefore, the tri-step identification of FTIR is a time-saving; accurate, cost-saving and convenient method to effectively distinguish traditional Chinese medicines.

[Study on Panax notoginseng and its processed products by FTIR spectroscopy].

The chemical differences of panax notoginseng before and after processing were analyzed by Fourier transform Infrared spectroscopy (FTIR) combined with two-dimensionalcorrelation spectroscopy (2D-IR). Compared with conventional IR spectra of the samples, the FTIR spectra of panax notoginseng and its processed products were similar in the range of 1 200-400 cm(-1). The difference was that prepared panax notoginseng had strong and characteristic peaks at 2 925, 2 855, 1 746, 1 460, 1 376 and 1 158 cm(-1), which all arose from the characteristic vibration of peanut oil. This was because there was some peanut oil left in the panax notoginseng, when panax notoginseng after processing. Obvious differences were observed between 2D-IR spectra of them, in the range of 1 400-1 700 cm(-1), there was only one auto peaks at 1 650 cm(-1) in the spectra of panax notoginseng, but there were auto peaks at 1 469 and 1 640 cm(-1) in the spectra of prepared panax notoginseng. In the range of 1 400-1 700 cm(-1), the 2D-IR spectra of panax notoginseng and its processed product present characterstic peaks at 1 139 (1 137), 1 194 (1 196), 1 121 (1 221)cm(-1) respectively, but the relative intensities of auto peaks were changed. For example, auto peak around 1 139 cm(-1) was enhanced, but auto peak around 1 194 cm(-1) was weakened. The results of 2D-IR correlation spectroscopy indicated the decomposition of flavonoids, saccharides and saponins. This method can track dynamically the processing procedure of panax notoginseng and reveal the main tansformations, so it can explain the pharmacology of panax notoginseng and its processed product by FTIR and 2D-IR.

[Analysis of different parts and tissues of Panax Notoginseng by Fourier transform infrared spectroscopy].

The techniques of Fourier transform infrared (FTIR) spectroscopy were applied to analyze the different parts and tissues of Panax Notoginseng (Sanqi, SQ), i.e. rhizome, main root, rootlet, fibrous root, xylem, cambium, phloem and epidermis. Both the FTIR spectra and second derivative spectra of these various parts and tissues of SQ samples were found to be similar. Their dominant component is starch resulting from the characteristic peaks of starch observed at 3 400, 2 930, 1 645, 1 155, 1,080 and 1,020 cm(-1) on the spectra of all these SQ samples. However, the varieties of peaks were found on the spectra among these specific samples. The rhizome contains more saponins than others on the basis of the largest ratio of the peak intensity at 1,077 cm(-1) to that at 1,152 cm(-1). The peaks located at 1 317 and 780 cm(-1) on the FTIR spectra of the rhizome and its epidermis indicate that the two parts of SQ samples contain large amount of calcium oxalate, and its content in the latter is relative larger than that in former. The fibrous root contains much amount of nitrate owing to the obvious characteristic peaks at 1 384 and 831 cm(-1). For the difference among the various tissues of SQ samples, the peaks at 2,926, 2,854 and 1,740 cm(-1) on the FTIR spectra of epidermis is the strongest among the various tissues of main root indicating the largest amount of esters in epidermis. Protein was also found in the cambium of the main root based on the relative strong peaks of amide I and II band at 1,641 and 1,541 cm(-1), respectively. The results indicate that FTIR spectra with its second derivative spectra can show the characteristic of the various parts and tissues of SQ samples in both the holistic chemical constituents and specific chemical components, including organic macromolecule compounds and small inorganic molecule compounds. FTIR spectroscopy is a useful analytical method for the genuine and rapid identification and quality assessment of SQ samples.

[Study on Dendrobium loddigesii Rolfes from different regions and harvest periods by FTIR].

Infrared Spectroscopy (IR) integrated with two dimensional correlation infrared spectroscopy (2DCOS IR) was employed to rapidly discriminate Dendrobium loddigesii Rolfes (DR) from different regions and harvesting periods. The results showed that the IR peaks around 1 035, 1 051, 1 078, 1 156, 1 500, 1 511 and 1 736 cm-1had perceptible differences among DRs from different regions, indicating that different DRs containing remarkable different compositions and contents of polysaccharides, ketones and esters. 2DCOS IR spectra of DRs from Vietnam, Yunnan, Guangxi, Guizhou each had seven, eight, eight, nine auto peaks, respectively; furthermore, DRs from Guagnxi had the strongest peak in 1 220 cm-1, which was distinguish to those of other DRs (980 cm -1). In the IR spectra of DRs from different harvest seasons, the wave number of key peaks in (1 034 approximately1 023)cm- 1, the wave number of minor peaks in (1 6174)cm-1, as well as the presence of peaks in 1 078(1 076, 1 079)cm-1, showed obvious periodic changes with the seasons, which indicated the accumulation of polysaccharides and ketones from DRs displayed an evident periodic variability discipline. The application of FTIR in DRs could facilitate acquiring their growth conditions, composition and content changes, which would be significant in rational exploitations and utilizations of DR

[Analysis and identification of Poria cocos peels harvested from different producing areas by FTIR and 2D-IR correlation spectroscopy].

Different geographical regions of traditional Chinese medicine (TCM), its chemical composition is different, the accumulation of drug and medicinal properties is different. The accurate identification and analysis of different production area of medicinal herbs is critical for the quality control and pharmacological research of TCM. In this paper, a tri-step infrared spectroscopy (Fourier transform infrared spectroscopy (FTIR) combined with second derivative spectra and two-dimensional correlation infrared spectroscopy (2D-COS) were employed to identify and analyze the main components of Hubei (HB), Anhui (AH), Yun-nan (YN) genuine Poria Cocos peels. The emergence of several characteristic absorption peaks of carbohydrates including 1149, 1079 1036 cm(-1), peaks around 1619, 1315, 780 cm(-1) belonged to calcium oxalate suggested that HB and AH Poria Cocos peels contained calcium oxalate, but peaks around 797, 779, 537, 470 cm(-1) belonged to kaoline suggested that YN Poria Cocos peels contained kaoline. Their carbohydrates were different by comparing the second derivative infrared spectra in the range of 1640-450 cm(-1) and Yongping come from YN contains both calcium oxalate and kaoline. Furthermore, the above differences were visually validated by two-dimensional correlation spectroscopy (2D-COS). It was demonstrated that the Tri-step infrared spectroscopy were successfully applied to fast analyze and identify Poria Cocos peels from different geographical regions and subsequently would be applicable to explain the relevance of geographical regions and medicinal properties for the TCM.