Applied Radiation and Isotopes 86 (2014) 118–125

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PIXE and GC–MS investigation for the determination of the chemical composition of Syrian Cuminum cyminum L M.S. Rihawy n, E.H. Bakraji, A. Odeh Department of Chemistry, Atomic Energy Commission, PO Box 6091, Damascus, Syrian Arab Republic

H I G H L I G H T S


To our knowledge, there is no published studies focus on the Syrian cumin composition (neither elemental nor essential oil components) in spite of its valuable medicinal importance in the country.
This work is basically dedicated to investigate both elemental content and essential oil component of the Syrian cumin seeds.
The elemental analysis was performed using PIXE, a very powerful elemental analysis technique and the essential oil components were determined using GC–MS.

art ic l e i nf o

a b s t r a c t

Article history: Received 8 April 2013 Received in revised form 18 December 2013 Accepted 7 January 2014 Available online 21 January 2014

The chemical composition and concentration of Syrian cumin (Cuminum cyminum L.) were investigated. The particle-induced X-ray emission (PIXE) analytical technique was used to analyze a wide range of elements from Mg to Sr. The advantages and disadvantages of the PIXE technique in plant material elemental analysis are discussed. A high level of iron was detected in the cumin samples, clarifying the possible contribution of cumin to maintaining the immune system. The contribution of the elements in cumin seeds to the dietary recommended intakes (DRI) of elements was evaluated. Additionally, GC–MS measurements were performed to determine the chemical composition of cumin essential oil. Twentyone components were identified, and cuminaldehyde, γ-terpinene, o-cymene, limonene and β-pinene were determined to be the major constituents. A correlation between the chemical composition of cumin seeds and their use as a traditional remedy is proposed. & 2014 Elsevier Ltd. All rights reserved.

Keywords: Cuminum cyminum L Essential oils Elemental analysis PIXE GC–MS

1. Introduction Cumin (Cuminum cyminum L) has been cultivated in Syria for centuries. Syrian cumin is one of Syria’s national sources of income (Thomas, 2004), and it is in high demand worldwide because of its high quality (Hamwi, 2006). It has been reported that Syria, Pakistan and Turkey are the leading exporters of cumin (Small, 2006). The northern part of Syria is the source of more than 75% of Syrian cumin (in both Aleppo and Idleb counties). Cumin has been investigated extensively in the literature; considerable attention has been given to its physical (Singh and Goswami, 1996), thermal (Singh and Goswami, 2000) and medicinal properties. Its medicinal properties are well described in the literature; attributes such as reducing blood glucose levels (Roman-Ramos et al., 1995), maintaining the nervous and immune systems (Parthasarathy et al., 2008) and being both antimicrobial (Shetty et al., 1994) and

n

Corresponding author. Tel.: þ 963 11 2132580; fax: þ 963 11 6112289. E-mail address: cscientifi[email protected] (M.S. Rihawy).

0969-8043/$ - see front matter & 2014 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.apradiso.2014.01.003

antioxidant (Hajlaoui et al., 2010) have been reported. The use of cumin as a digestive aid has also been documented (Milan et al., 2008). It is used traditionally to give a special flavor to many dishes, owing to its distinctive bitter taste and warm strong aroma. People drink its decoction to combat stomach disorders, diarrhea, gas, flatulence and colic. It is one of the first spices to be introduced locally to infants to alleviate their stomach pains. The chemical composition of cumin has also been described in the literature; interest has focused on both its elemental profile (Ansari et al., 2004; Singh and Garg, 2006) and essential oil components (Hajlaoui et al., 2010; Jalali-Heravi et al., 2007). Gas chromatography coupled to mass spectrometry (GC–MS) (Kitson et al., 1996) has been used extensively to determine the components of the essential oils of medicinal plants (GC–MS is used for both qualitative and quantitative analysis). It is important to understand the effects of the trace elements in medicinal plants on human health (Lovkova et al., 2001) because they play an important role in creating the active chemical components present in the body (King, 1989). Furthermore, the correlation between the elemental profiles in a medicinal plant and its traditional use as a

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remedy merits investigation (Mohanta et al., 2003; Pereira and Felcman, 1998). The use of ion beam analysis (IBA) techniques for elemental analysis (Malmqvist, 2004) has grown because these techniques combine the advantages of being non-destructive and multielemental. They can be used alone or in combination to obtain information about the system being studied. The particleinduced X-ray emission (PIXE) analytical technique (Johansson and Campbell, 1988; Johansson et al., 1995) is another IBA technique that involves the production of X-rays characteristic of the atoms present in the sample due to the atomic excitation caused by high energy charged particles. PIXE was first introduced by Johansson et al. (1970). The advantages of PIXE technique make it appropriate for elemental analysis of plant materials. Most important major, minor and trace elements (from sodium to uranium) can be determined in a single run of a large number of samples in a relatively short time. In addition, it is very easy to prepare plant samples for analysis (i.e., it is sufficient to dry the sample and mount it in the target chamber). The increasing use of ion beam accelerators around the world and the recent development of IBA techniques have encouraged researchers to employ these powerful techniques in different analytical applications, including the investigation of elements in medicinal plants. IBA techniques have been utilized successfully during the past ten years to perform elemental analyses of medicinal plants (Devi et al., 2008; Olabanji et al., 2006; Rihawy et al., 2010; Stihi et al., 2000). To our knowledge, there are no published studies focusing on the composition of Syrian cumin (neither its elemental components nor its essential oil components) despite its medicinal value and importance in this country. The objective of this work was to determine both the elemental profile of Syrian cumin seeds and the chemical composition of its essential oil using the PIXE and GC–MS techniques, respectively, and to verify the presumed correlation between its composition and its traditional usage.

2. Experimental 2.1. Materials Cumin seeds samples were obtained from both the Aleppo and Idleb regions in the northern part of Syria. The solvents used in both the extraction and GC–MS measurements were methanol, dichloromethane and acetone, all purchased from Merck, Darmstadt, Germany. Their purity was of HPLC grade, and they were used as received without further purification.

2.2. Sample preparation 2.2.1. For PIXE measurements Cumin seed samples were obtained from local shops in Aleppo and Idleb. First, they were washed thoroughly with distilled water to remove any dust from the surface and were subsequently dried in an oven at 40 1C for 72 h. Then, the cumin seeds were milled into a fine powder using a mortar agate and were subsequently sieved using a 100 μm mesh. One hundred milligrams of the cumin powder was encircled in 500 mg of boric acid powder, as a binder, and pelletized using a 75 kN press and a cylindrical mold of 14 mm diameter to obtain 2.3-mm-thick pellets. Cumin seeds are considered to be thick insulating samples for PIXE analysis in a vacuum, and hence, no direct beam current measurement was possible. Additionally, the effect of the charge build-up process on the thick insulating samples in the vacuum is considerably enhanced, which causes significant background noise in the entire

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PIXE spectrum that screens all the characteristic X-ray peaks. Coating with a very thin layer of carbon is one of the simplest methods used to overcome these problems. However, this is a time-consuming process and could introduce unwanted trace elements. We omitted the carbon-coating process to prevent any possibility of sample contamination during the preparation. The charging effect on thick insulating targets was absent in our vacuum chamber because an electron flood gun (from a tungsten filament) had been placed in front of the sample, which compensated for the charge build-up of the insulating surface. Three different cumin samples from each region (Aleppo and Idleb) were prepared. The IAEA-V10 (hay powder) (Pszonicki and Hanna, 1985) and IAEA-359 (cabbage powder) (Campbell et al., 2000) reference materials were prepared in the same way to be used in both verification and quantification studies. The samples were maintained under drying conditions at 40 1C for 24 h prior to the PIXE analysis in the vacuum chamber. 2.2.2. For GC–MS measurements The extraction and isolation of the cumin essential oils were performed as follows. The seeds were first cleaned and dried at room temperature. Subsequently, 50 g of the dried seeds was milled into a fine powder (to enhance the oil yield by hydrodistillation) and subjected directly (to prevent oil loss and decomposition) to hydrodistillation for 3 h with 500 ml distilled water using a glass-Clevenger type system. The oil obtained was dried over anhydrous sodium sulfate and kept in dark glass vials at 4 1C prior to the GC–MS measurements. 2.3. PIXE experimental system and measurements PIXE measurements were performed using an MeV ion beam generated by a 3 MV HVEE™ tandem accelerator (Mous et al., 1995) at the Atomic Energy Commission of Syria (AECS). The cumin samples were irradiated with an incident beam normal to their surface with a current that did not exceed 2 nA. This current causes a negligible heat effect to the sample surface that can cause major changes to the main structure of the cumin samples (Peach et al., 2006). Moreover, the beam heating effect of the sample surface is minimized as a result of the design of our sample holder. Our “wheel“ target holder was designed at HVEE™ and can accommodate up to 25 samples at the same time. Each sample is placed in a separate hole and fixed to the holder by a copper clip on the rear surface, while the front surface of the sample faces the beam. Each hole is designed to provide good electrical and thermal conductivity between the sample surface and the holder because the outer surface of the sample is properly connected to the sample holder. Fig. 1 shows a sketch diagram of a cross sectional view of the sample holder together with the sample. The proton beam was collimated to dimensions of 2  2 mm2 using two sets of slits located at the beam line. The accumulated beam charge was measured indirectly using a beam profile monitor device (BPM), which is located in the beam line directly behind the vacuum chamber. We have successfully utilized this novel method for monitoring the accumulated beam charge (Ismail and Rihawy, 2013). Secondary electron suppression was achieved by applying both þ60 V to the target holder and  60 V to a hollow copper plate placed in front of the sample holder. The PIXE data were collected using a 30 mm2 (Si)Li X-ray detector (DSG type PGP-30-165) with a Be window of 25.4 mm in thickness and a measured FWHM of 158 eV at 5.9 keV. The detector is placed at 451 to the beam axis. Additionally, backscattered protons were collected to obtain the backscattering spectra using a PIN photodiode device that can be successfully utilized as a radiation

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elements are integral to the software and can be used effectively for quantitative analysis of C, N, and O. The PIXE data were analyzed using GUPIXWIN V1.3, the Windowss interface to GUPIX (Campbell et al., 2010) software, that can simply, automatically and quickly fit the PIXE spectra to obtain the elemental concentrations. Our PIXE system was calibrated using a wide range of pure single-element standards emitting both K and L X-rays in the 1.041–25.191 keV energy region. The Trace Solution mode was used in the software, where the known composition obtained from the EBS spectra was entered into the software. The results were verified by comparing them with those obtained from the IAEA-V10 and IAEA-359 reference materials. 2.4. GC–MS experimental system and measurements

Fig. 1. A sketch diagram showing a cross sectional view of the sample holder together with the sample.

detector (JIMÉNEZ, 2008) and that is considered a simple, low-cost tool. This device is placed at a distance of 14 cm from the sample holder and at a detection angle of 1701. Its performance as an elastic backscattering (EBS) detector was initially tested using a SiO2/Si reference sample (BCR CRM 564-120.19B4). For the analysis of the low-Z matrix elements present in the samples with low X-ray energies, a 1 MeV proton beam was found to be sufficient to induce the X-rays characteristic of the major elements (i.e., Mg, Al, Si, P, S, Cl, K, Ca, and Fe). The use of low beam energy, together with a low beam current, guarantees low counting rates of the X-rays from the low-Z major elements to prevent degradation of the X-ray peak shapes. The beam current was set to 2 nA, and the collected charge was 2 μC (the acquisition time was approximately 15 min per sample). The count rate did not exceed 500 counts/s. By contrast, the analysis of the heavier trace elements (with higher characteristic X-ray energies) was performed using 3 MeV protons. The increase in charged particle energy is associated with an increase in the X-ray production cross sections of all the elements. Placing a suitable filter in front of the detector window eliminates the contribution of low energy X-rays of the matrix elements and therefore enhances the dynamic range of the response of the spectrometry system, thereby increasing the sensitivity to higher-energy characteristic X-rays from trace elements. Therefore, an Al filter of 180 μm thickness was used. The proton beam current was set to 2 nA, and the data acquisition time was considered to be long enough to obtain reasonable counting statistics (the collected charge was 7 μC, which takes about 1 h per sample to collect). The trace elements Ni, Cu, Zn, Br, Rb, and Sr were clearly detected. Matrix effects were taken into account by collecting elastic backscattered (EBS) particles, and the matrix composition could be derived from the shape of the EBS spectrum. The simultaneous EBS/PIXE data acquisition was not possible due to the light emission induced from the tungsten filament. Therefore, the EBS spectra were collected individually when the tungsten filament was turned off. The data were recorded using MCDWIN software v.2.87 from FAST ComTec. The analyses of the backscattering spectra were performed using SIMNRA software (Mayer, 1999). The experimental data on the elastic scattering cross-section of protons on light

The analyses of the essential oil components were performed using an Agilent GC–MS system in which an HP-6890-series II GC system equipped with a 5973 mass selective detector was connected to an HP5-MS capillary fused-silica column (dimensions of 30 m, 0.25 mm with film thickness of 0.25 μm). Helium gas with a flow rate of 0.9 ml/min was used as a carrier. The oven temperature was automatically controlled; it was initiated at 50 1C for 1 min, increased to 280 1C at steps of 5 1C/min and subsequently held isothermally for 20 min. The temperatures of the injector port and the detector were 250 1C and 280 1C, respectively, with a split ratio of 1:50. A 1 μl volume of a 1% solution (diluted in hexane) was injected in the column at a fragment energy of 70 eV with a scan mass range of 50–500 amu. Agilent ChemStation software (Agilent-Technologies, 2010) was used to process the mass spectra and chromatograms. The chemical components of the oil were determined by a comparison of their mass spectra with those in both the Wiley GC–MS library and (Adams, 2007).

3. Results 3.1. PIXE results Fig. 2 shows two overlaid PIXE spectra of cumin seeds from the Idleb region, using the two experimental conditions described above, where the Kα and Kβ X-ray peaks of a wide range of elements from Mg to Sr are clearly shown. V, Cr and Mn are not visible in both spectra because a more appropriate filter was needed. This would have required a third round of data acquisition, which we determined to be too time consuming for this investigation. Moreover, the use of a funny filter was also found to be ineffective when small currents were used. Fig. 3 shows the experimental elastic backscattering (EBS) spectra of the protons on the cumin seeds of the Idleb region together with the SIMNRA program fit, where the C, N, O and Ca surface edges are clearly shown. The proton energy used was 3 MeV, with a current of 2 nA and an accumulated charge of 2 μC. The fitting of the EBS spectra enabled matrix element determination of the cumin seeds from the Aleppo and Idleb regions. The PIXE verification study for the determination of the concentrations of elements in the plant substances was performed using the IAEA-V10 and IAEA-359 reference materials. Table 1 shows the obtained elemental concentrations for the reference materials as a mean value of three PIXE measurements together with the standard deviation, accuracy, precision and limit of detection. Table 2 summarizes the mean values of the elemental concentrations of triplicate PIXE measurements of the cumin seeds from the Aleppo and Idleb regions7 the standard deviation together

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Fig. 2. The PIXE spectrum of Cuminum cyminum L from the Idleb region.

Fig. 3. The backscattering spectrum of Cuminum cyminum L from the Idleb region.

with the dietary recommended intakes (DRI) for each element according to (National-Academies, 2004).

3.2. GC–MS results The GC–MS results for both the qualitative and quantitative analyses of the components of the essential oil of cumin seeds are summarized in Table 3, in which 21 compounds were clearly identified.

4. Discussion From the PIXE verification study of the plant, it is clear that accuracy and precision are strongly affected by the experimental conditions. For the analysis of the major elements, both the accuracy and precision were found to be less than 10% in most cases. By contrast, the analyses of the trace elements revealed a few limitations in terms of precision and accuracy for some elements. These limitations arose mainly due to the pronounced counting statistical uncertainty for these elements due to an

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Table 1 The PIXE elemental concentrations of the thick IAEA V-10 and IAEA 359 reference materials.

IAEA V10 (Hay powder) 1 MeV protons- Mylar filter 6 μm thick

3 MeV protons- Al filter 180 μm thick

IAEA 359 (Cabbage powder) 1 MeV protons- Mylar filter 6 μm thick

3 MeV protons- Al filter 180 μm thick

Element

Recommended (μg/g)

95% C.I.a(μg/g)

Mean 7 SDb(μg/g)

Ac(%)

RSDd (%)

LODe(μg/g)

Mg Si P S Cl K Ca

1360 NCf 2301 NC NC 21000 21600

1330–1450 nnnnn 2101–2500 nnnnn nnnnn 19600–22500 21000–22200

1572.2 7 224.7 1628.3 7 58.2 2236.4 7 171.1 2966.17 230.8 9002.7 7 611.2 23659.3 7 2257.9 23160.3 7 1814.5

15.6% nnnnn 2.8% nnnnn nnnnn 12.7% 7.2%

14.3 3.6 7.7 7.8 6.8 9.5 7.8

307 69 67 61 84 93 251

Fe Cu Zn Br Rb Sr

186 9.4 24 8 7.6 40

177–190 8.8–9.7 23–25 7–11 7.3–7.8 37–44

152.7 7 4.9 11.4 7 0.2 26.7 7 4.2 9.2 7 1.4 7.3 7 3.0 46.9 7 4.5

17.9% 20.7% 11.3% 15.0% 3.9% 17.3%

3.2 1.9 15.9 15.4 40.7 9.6

Mg Si P S Cl K Ca

2160 NC NC NC NC 32500 18500

2110–2210 nnnnnn nnnnnn nnnnnn nnnnnn 31810–33190 17990–19010

3.3% nnnnnn nnnnnn nnnnnn nnnnnn 1.9% 1.9%

12.5 14.1 13.8 11.6 10.2 6.0 6.7

Fe Cu Zn Br Rb Sr

148 5.67 38.6 NC NC 49.2

144.1–151.9 5.49–5.85 37.9–39.3 nnnnnn nnnnnn 47.8–50.6

5.6% 23.3% 1.6% nnnnn nnnnn 10.9%

0.6 1.6 6.1 11.9 17.5 17.6

2089.4 7 261.3 736.2 7 104.0 4929.57 681.2 15547.6 7 1805.5 9177.17 938.0 33128.3 7 1989.8 18857.7 7 1257.4 139.7 7 0.8 4.4 7 0.1 39.2 7 2.4 5.4 7 0.6 6.9 7 1.2 43.9 7 7.7

16.9 2.8 2.4 2.6 3.9 4.8 317 65 78 94 70 105 254 16.1 2.4 3.7 1.7 3.2 4

a

Confidence interval. Mean value of three PIXE measurements together with the standard deviation. c Accuracy calculated by the absolute difference between the obtained results and the reference values. These are expressed as percentage values. d Relative standard deviation as a measurement of precision. e Limit of detection. f Non-certified value. b

insufficient acquisition time, even though the acquisition time for each sample was approximately 1 h. The proton beam current used was small (only 2 nA), and if higher currents were used, a black spot was clearly noticed on the samples, which may indicate a major change in the plant composition due to temperature effects introduced by beam heating (Kwiatek et al., 1996). However this optical signature of damage does not necessarily mean that the main composition has changed noticeably. Further investigation is required to obtain the optimum beam current that guaranties same elemental concentrations before and after beam irradiation. A recent article review that deals with the best practice for minimizing beam induced damage during IBA has been edited by Benzeggouta and Vickridge (2013). The limitation of PIXE, mentioned above, in the analysis of the trace elements in plants raises the following question: is PIXE an ideal technique for the determination of trace elements in plant materials? PIXE is a simple, direct and multielemental analytical method for the investigation of the elements present in plant materials. The analysis of the major elements, of low energy X-rays, is ideal, especially when the PIXE is combined with the EBS technique to identify the matrix elements (i.e., C, N, O elements). However, some difficulties arise in the study of trace elements using high energy X-rays; high proton energies are required to increase the production of cross sections of the X-rays of heavy trace elements. High beam currents are also required to minimize the acquisition time, but they may burn plant samples. Very long data acquisition times are required to perform an analysis of trace elements. Other non-destructive techniques, such as the XRF technique, might be more suitable for the analysis of trace elements in plant materials. It has been reported that XRF is more sensitive for heavy elements

with higher X-ray energies than PIXE and vice versa (Ali, 2004; Benyaich et al., 1997). The XRF technique is relatively simple and can be performed at a low cost compared with PIXE. The unique feature of PIXE is that it can be used simultaneously with the other ion beam analysis techniques to effectively perform what so called “Total-IBA” (Jeynes et al., 2012) to derive the elemental concentration of all elements in the periodic table. For instance, EBS technique is usually combined with PIXE, which is essential for identifying the matrix elements in the sample. Moreover, the EBS technique has recently been used by some XRF groups (e.g., (Bamford et al., 2004)) to identify the matrix elements. Generally speaking, PIXE and XRF are considered to be complementary rather than competitive. In fact, a comprehensive TXRF/XRF study (Khuder et al., 2009) of plant materials was carried out in our institution and demonstrated elemental concentrations with errors of less than 10% for trace elements (heavier than Ca). The elemental concentrations of cumin seeds from the Aleppo region tend to be lower than those from the Idleb region, as shown in Table 2. Such differences normally arise from the geographic origin and storage conditions. The two obtained values for each element in each region were arithmetically averaged and are also presented in Table 2. Most of the PIXE results of the elemental profiles of the Syrian cumin seeds are within the range of previous reported values of cumin seeds from other countries (Azeez, 2008; Özcan and Akbulut, 2007; Singh and Garg, 2006). The results of the present study have shown that cumin is a very good source of iron, with a concentration of approximately 2 mg/g of cumin seeds. This means that 1 teaspoon of cumin seeds (equivalent to 2 g) will contribute more than 25% of the dietary recommended intake (DRI) of iron. The promotion of iron adsorption in the body

1 1 10 – – – 15.70 16.39 13.47 13.81 22.73 10.11 11 7 2 24 7 4 36 7 5 25 7 3 872 127 7 13 31.66 12.51 12.16 34.02 13.69 4.37 7.27 2.3 21.97 2.7 34.5 7 4.2 7.57 2.6 10.6 7 1.4 79.6 7 3.5 6.5 19.8 30.7 4.6 11.5 82.8 5.4 20.9 33.8 9.4 8.9 75.9 9.8 25 39 8.5 11.3 80.1

b

a

Mean value of three PIXE measurements together with the standard deviation. Arithmetic average of the mean values for each element of both the Aleppo and Idleb regions. c Relative standard deviation as a measurement of precision. d Limit of detection. e Dietary recommended intakes of elements.

17.48 28.18 23.23 15.10 58.11 14.60 14.6 7 2.6 26.3 7 7.4 37.97 8.8 41.97 6.3 6.0 7 3.5 173.9 7 25.4 14.4 25.2 45.6 49.2 7 198 17.3 19.5 39.8 38.5 2.1 147.4 12.2 34.2 28.3 38 8.8 176.3 Ni Cu Zn Br Rb Sr 3000 keV protons- Al filter 180 μm thick

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Table 3 The chemical components of the essential oil of cumin seeds from the Aleppo and Idleb regions.

3.5 3.5 3.0 2.7 5.3 5.3

400 – – 700 – 2300 4500 1300 15 341 128 54 58 43 40 69 300 221 6.76 13.52 11.27 9.29 6.17 7.59 7.02 5.30 9.62 5341 7 361 3141 7 425 8131 7 916 1810 7 168 5994 7 370 5805 7 441 32743 7 2298 17337 7 920 2040 7 196 4778 7 359 2018 7 443 5966 7 1272 2314 7 266 47567 398 4038 7 514 28973 7 2572 18450 7 1376 1366 7 195 4957 2389 7305 2413 4933 4209 30315 19227 1571 4365 1528 4772 2013 4301 3460 26007 16862 1344 10.60 17.00 12.81 15.77 8.62 9.45 10.43 7.52 12.55 5904 7 626 4264 7 725 10296 7 1319 1306 7 206 72337 624 75727 716 365127 3809 162247 1221 27147 341 5196 3488 8868 1076 6572 6899 32625 14959 2324 6134 4382 10553 1366 7316 7491 36675 16317 2865 6383 4923 11467 1475 7811 8324 40237 17395 2954 Mg Al Si P S Cl K Ca Fe 1000 keV protons- Mylar filter 6 μm thick

Run 2 (μg/g) Run 1 (μg/g) RSD (%)

Mean 7SD (μg/g) Run 3 (μg/g) Run 2 (μg/g) Run 1 (μg/g)

5013 2136 5820 2516 5035 4444 30597 19262 1183

Mean7 SD (μg/g) Run 3 (μg/g)

7.51 21.93 21.33 11.48 8.37 12.73 8.88 7.46 14.27

A. Av.7 SDb (μg/g) RSD (%)

Syrian cumin

c a

Aleppo cumin

c a

Idleb cumin Element

Table 2 The elemental concentrations (in μg/g) of the cumin seeds ( 7 standard deviation) from the Aleppo and Idleb regions together with the dietary recommended intakes (DRI) of each element.

RSDc (%)

LODd (μg/g)

DRIe (mg/day)

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No

Compounds identified

% In Idleb region

% In Aleppo region

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

α-Thujene α-Pinene Sabinene β-Pinene β-Myrcene α-Phellendrene 3-Carene o-Cymene Limonene γ-Terpinene Linalool cis-Sabinene hydrate Verbenol trans-Pinocarveol Terpinene-4-ol trans-Carveol Cuminaldehyde Phellandral 2-Caren-10-al Myrtenal β-Caryophyllene Total %

0.31 0.37 0.67 11.50 0.80 0.22 0.62 10.98 1.47 12.62 0.19 0.39 0.23 1.38 0.89 5.71 38.5 0.59 7.35 2.12 0.65 97.56

1.40 1.10 1.30 10.30 0.52 0.14 1.68 9.74 3.22 16.3 1.40 0.53 0.66 1.80 0.22 3.20 32.8 0.36 6.24 3.30 0.27 96.48

is enhanced by cumin (El-Shobaki et al., 1990), making cumin an active factor for increasing the bioavailability of iron. Iron plays a vital role in human health; it is an essential component of blood hemoglobin and contributes to the maintenance of a healthy immune system (Broome and Marks, 1998). Additionally, our GC–MS results are within the range of previously reported values for the essential oil components of cumin seeds from other countries (El-Sawia and Mohamed, 2002; Hajlaoui et al., 2010; Jalali-Heravi et al., 2007). The essential oil yield of the cumin seeds from both sites was approximately 1.4 g/100 g dry weight. It is necessary to study the biological effects of essential oils of medicinal plants (Bakkal et al., 2008) to determine the correlation between their content and their medical usage. Most major components of the essential oil of Aleppo’s cumin seeds are higher than or comparable with those for Idleb’s cumin seeds. Both the characteristic odor and bitter taste of cumin seeds exist mainly due to the presence of cuminaldehyde (Sahana et al., 2011), which is the most abundant constituent of cumin oil. Cumin has both calming and anti-infectious properties due to the therapeutic effects of the aldehyde compounds present (Bowles, 2003). β-pinene comprises more than 10% of the volume of cumin oil. It also has both antiinflammatory (Karaca et al., 2007) and antimicrobial properties (Tajkarimi et al., 2010), which help to enhance the immune system. These advantages enhance the activity of iron in cumin, which also helps to boost the immune system. Therefore, after considering this work and other works related to the health benefits of cumin, it might be advisable to consume cumin seeds in the form of either an herbal tea or as a pressed oil on a regular basis. Its daily recommended dosage is 300 to 600 mg (equivalent to one-quarter teaspoon), according to the physician’s desk reference (PDR) for herbal medicines (Gruenwald et al., 2000). One should take into consideration that fine grinding of the cumin seeds can cause a loss of 50% of the volatile oils within 1 h (Khare, 2007).

5. Conclusion The elemental profile and the essential oil components of Syrian cumin seeds were investigated using PIXE and GC–MS techniques, respectively. The PIXE elemental analysis technique

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has been shown to be a simple, direct and multielemental analytical method for the investigation of the elements present in medicinal plants. However, limitations in the determination of some trace elements might arise due to the counting statistical uncertainty caused by an insufficient data acquisition time. PIXE results have shown that cumin is a good source of iron. The GC–MS results revealed that the major components in the essential oil of cumin seeds are cuminaldehyde, γ-terpinene, O-cymene, limonene and β-pinene. Correlations between both the elemental profile and the essential oil components of cumin seeds with their therapeutic effects were evaluated.

Acknowledgments The authors gratefully acknowledge Prof. I. Othman, Director General of the AECS, for his invaluable assistance during the progress of this work. Thanks are also due to the head of the chemistry department, Prof. T. Yassine, for all his support. The technical assistance received from the accelerator staff is also highly appreciated.

References Adams, R., 2007. Identification of Essential Oil Components by Gas Chromatography/Mass Spectrometry, fourth ed. Allured Publishing Corporation, Carol Stream, IL, USA. Agilent-Technologies, 2010. Agilent ChemStation Manual. © Agilent Technologies, Printed in Germany. Ali, M., 2004. PIXE and RIXRF comparison for applications to biological sample analysis. Nucl. Instrum. Methods Phys. Res., Sect. B 222, 567–576. Ansari, T.M., lkram, N., Najam-ul-Haq, M., Fayyaz, I., Fayyaz, Q., Ghafoor, I., Khalid, N., 2004. Essential trace metal (zinc, manganese, copper and iron) levels in plants of medicinal importance. J. Biol. Sci. 4, 95–99. Azeez, S., 2008. Cumin. In: Parthasarathy, V.A., Chempakam, B., Zachariah, T.J. (Eds.), Chemistry of Spices. CABI, Oxfodshire, UK, pp. 211–226 Bakkal, F., Averbeck, S., Averbeck, D., Idaomar, M., 2008. Biological effects of essential oils—a review. Food Chem. Toxicol. 46, 446–475. Bamford, S.A., Jaksic, M., Medunic, Wegrzynek, D., Chinea-Cano, E., Markowicz, A., 2004. Extending the quantitative analytical capabilities of the EDXRF technique for plant-based samples†. X-ray Spectrom. 33, 277–280. Benyaich, F., Makhtari, A., Torrisi, L., Foti, G., 1997. PIXE and XRF comparison for applications to sediments analysis. Nucl. Instrum. Methods Phys. Res., Sect. B 132, 481–488. Benzeggouta, D., Vickridge, I., 2013. Handbook on Best Practice for Minimising Beam Induced Damage during IBA. arXiv 1303.3171. Bowles, E.J., 2003. The Chemistry of Aromatherapeutic Oils, third ed. Allen & Unwin, Crows Nest, Australia. Broome, C.V., Marks, J.S., 1998. Recommendations to Prevent and Control Iron Deficiency in the United States. In: Holloway, B.R., Dean, A.G. (Eds.), Morbidity and Mortality Weekly Report. U.S. Department of Health and Human Services, Atlanta, Georgia. Campbell, J.L., Boyd, N.I., Grassi, N., Bonnick, P., Maxwell, J.A., 2010. The Guelph PIXE software package IV. Nucl. Instrum. Methods Phys. Res., Sect. B 268, 3356–3363. Campbell, M.J., Radecki, Z., A.Trinkl, Burns, K.I., 2000. Report on the Intercomparison Runs for the Determination of Trace and Minor Elements in Cabbage Material (IAEA-359), Analytical Quality Control Services, IAEA Agency’s Laboratories, Seibersdorf, Austria. Devi, K.N., Sarma, H.N., Kumar, S., 2008. Estimation of essential and trace elements in some medicinal planys by PIXE and PIGE techniques. Nucl. Instrum. Methods Phys. Res., Sect. B 266, 1605–1610. El-Sawia, S.A., Mohamed, M.A., 2002. Cumin herb as a new source of essential oils and its response to foliar spray with some micro-elements. Food Chem. 77, 75–80. El-Shobaki, F.A., Saleh, Z.A., Saleh, N., 1990. The effect of some beverage extracts on intestinal iron absorption. Z. Ernährungswiss 29, 264–269. Gruenwald, J., Brendler, T., Jaenicke, C., Mehta, M., Fleming, T., 2000. PDR for Herbal Medicines. Medical Economics Company, Inc, Montvale, New Jersey. Hajlaoui, H., Mighri, H., Noumi, E., Snoussi, M., Trabelsi, N., Ksouri, R., Bakhrouf, A., 2010. Chemical composition and biological activities of Tunisian Cuminum cyminum L. essential oil: a high effectiveness against Vibrio spp. strains. Food Chem. Toxicol. 48, 2186–2192. Hamwi, B., 2006. Cumin in Syria, Production & Trade, Commodity Brief No. 8. National Agricultural Policy Centre, Damascus, Syria. Ismail, I.M., Rihawy, M.S., 2013. Comprehensive method to analyze thick insulating samples using PIXE technique. Nucl. Instrum. Methods Phys. Res., Sect. B 296, 50–53.

Jalali-Heravi, M., Zekavat, B., Sereshti, H., 2007. Use of gas chromatography-mass spectrometry combined with resolution methods to characterize the essential oil components of Iranian cumin and caraway. J. Chromatogr. A 1143, 215–226. Jeynes, C., Bailey, M.J., Bright, N.J., Christopher, M.E., Grime, G.W., Jones, B.N., Palitsin, V.V., Webb, R.P., 2012. “Total IBA”—Where are we? Nucl. Instrum. Methods Phys. Res., Sect. B 271, 107–118. JIMÉNEZ, F.J.R., 2008. Test Procedure for PIN Diode Radiation Detectors, IAEA Coordinated Research Project on Development of Harmonized QA/QC Procedures for Maintenance and Repair of Nuclear Instruments. Instituto Nacional de Investigaciones Nucleares, MÉXICO. Johansson, S.A.E., Campbell, J.L., 1988. PIXE—A Novel Technique for Elemental Analysis. John Wiley & Sons, New York. Johansson, S.A.E., Campbell, J.L., Malmqvist, K.G., 1995. Particle-Induced X-ray Emission Spectrometry (PIXE). John Wiley & Sons, Inc, New York. Johansson, T.B., Akselsson, R., Johansson, S.A.E., 1970. X-ray analysis: elemental trace analysis at the 10  12 g level. Nucl. Instrum. Methods 84, 141–143. Karaca, M., Özbek, H., Him, A., Tütüncü, M., Akkan, H.A., Kaplanoğlu, V., 2007. Investigation of anti-inflammatory activity of bergamot oil. Eur. J. Gen. Med. 4, 176–179. Khare, C.P., 2007. Indian Medicinal Plants, An Illustrated Dictionary. Springer Science & BusinessMedia, LLC, New York, USA. Khuder, A., Sawan, M.K., Karjou, J., Razouk, A.K., 2009. Determination of trace elements in Syrian medicinal plants and their infusions by energy dispersive Xray fluorescence and total reflection X-ray fluorescence spectrometry. Spectrochim. Acta, Part B 64, 721–725. King, J.C., 1989. Essential and toxic trace elements in human health and disease, current topics in nutrition and disease, 18, 679 pp. J. Nutr. 119, 1534. Kitson, F.G., Larsen, B.S., McEwen, C.N., 1996. Gas Chromatography and Mass Spectrometry: A Practical Guide. Academic Press, Inc., San Diego, California. Kwiatek, W.M., Lekki, J., Dutkiewicz, E.M., Paluszkiewicz, C., 1996. Importance of matrix changes in PIXE elemental analysis. Nucl. Instrum. Methods Phys. Res., Sect. B 114, 345–349. Lovkova, M.Y., Buzuk, G.N., Sokolova, S.M., Kliment’eva, N.I., 2001. Chemical features of medicinal plants (Review). Appl. Biochem. Microbiol. 37, 229–237. Malmqvist, K.G., 2004. Accelerator-based ion beam analysis—an overview and future prospects. Radiat. Phys. Chem. 71, 817–827. Mayer, M., 1999. SIMNRA, a simulation program for the analysis of NRA, RBS and ERDA. In: Duggan, J.L., Morgan, I.L. (Eds.). Proceedings of the 15th International Conference on the Application of Accelerators in Research and Industry. American Institute of Physics Conference Proceedings, American Institute of Physics, pp. 541–544. Milan, K.S.M., Dholakia, H., Tiku, P.K., Veshveshwaraiah, P., 2008. Enhancement of digestive enzymatic activity by Cumin (Cuminum cyminum L.) and role of spent cumin as a bionutrient. Food Chem. 110, 678–683. Mohanta, B., Chakraborty, A., Sudarshan, M., Dutta, R.K., Baruah, M., 2003. Elemental profile in some common medicinal plants of India. Its correlation with traditional therapeutic usage. J. Radioanal. Nucl. Chem. 258, 175–179. Mous, D.J.W., Gottdang, A., Broek, R, v.d., Haitsma, R.G., 1995. Recent developments at HVEE. Nucl. Instrum. Methods Phys. Res., Sect. B 99, 697–700. National-Academies, 2004. Dietary Reference Intakes (DRIs): Recommended Intakes for Individuals, Food and Nutrition Board. Institute of Medicine, National Academies, Washington D.C Olabanji, S.O., Omobuwajo, O.R., Ceccato, D., Buoso, M.C., Poli, M.D., Moschini, G., 2006. Analysis of some medicinal plants in South-western Nigeria using PIXE. J. Radioanal. Nucl. Chem. 270, 515–521. Özcan, M.M., Akbulut, M., 2007. Estimation of minerals, nitrate and nitrite contents of medicinal and aromatic plants used as spices, condiments and herbal tea. Food Chem. 106, 852–858. Parthasarathy, V.A., Chempakam, B., Zachariah, T.J., 2008. Chemistry of Spices. CABI, Oxfodshire, UK. Peach, D.F., Lane, D.W., Sellwood, M.J., Painter, J.D., 2006. An assessment of surface heating during ion beam analysis II: Application to biological materials. Nucl. Instrum. Methods Phys. Res., Sect. B 249, 680–683. Pereira, C.E.D.B., Felcman, J., 1998. Correlation between five minerals and the healing effect of Brazilian medicinal plants. Biol. Trace Elem. Res. 65, 251–259. Pszonicki, L., Hanna, A.N., 1985. Report on the Intercomparison IAEA/V-10 of the Determination of Trace Elements in Hay Powder. IAEA, Vienna, Austria. Rihawy, M.S., Bakraji, E.H., Aref, S., Shaban, R., 2010. Elemental investigation of Syrian medicinal plants using PIXE analysis. Nucl. Instrum. Methods Phys. Res., Sect. B 268, 2790–2793. Roman-Ramos, R., Flores-Saenz, J.L., Alarcon-Aguilar, F.J., 1995. Anti-hyperglycemic effect of some edible plants. J. Ethnopharmacol. 48, 25–32. Sahana, K., Nagarajan, S, Rao, L.J.M., 2011. Cumin (Cuminum cyminum L.) seed volatile oil: chemistry and role in health and disease prevention. In: Preedy, V., Watson, R., Patel, V. (Eds.), Nuts and Seeds in Health and Disease Prevention, first ed. Elsevier Inc., Burlington & San Diego, USA, pp. 417–427. Shetty, R.S., Singhal, R.S., Kulkarni, P.R., 1994. Antimicrobial properties of cumin. World J. Microbiol. Biotechnol. 10, 232–233. Singh, K.K., Goswami, T.K., 1996. Physical properties of cumin seed. J. Agric. Eng. Res. 64, 93–98. Singh, K.K., Goswami, T.K., 2000. Thermal properties of cumin seed. J. Food Eng. 45, 181–187. Singh, V., Garg, A.N., 2006. Availability of essential trace elements in Indian cereals, vegetables and spices using INAA and the contribution of spices to daily dietary intake. Food Chem. 94, 81–89.

M.S. Rihawy et al. / Applied Radiation and Isotopes 86 (2014) 118–125

Small, E., 2006. Cuminum (cumin). In: Cavers, P.B. (Ed.), Culinary Herbs second ed. National Research Council of Canada, Ontario, pp. 340–346. Stihi, C., Popescu, I.V., Busuioc, G., Badica, T., Olariu, A., Dima, G., 2000. Particle induced X-ray emission (PIXE) analysis of Basella L alba leaves. J. Radioanal. Nucl. Chem. 246, 445–447.

125

Tajkarimi, M.M., Ibrahim, S.A., Cliver, D.O., 2010. Antimicrobial herb and spice compounds in food. Food Control 21, 1199–1218. Thomas, R., 2004. Khanasser Valley Integrated Research Site, Syria. UNESCO Publications—Drylands & Desertification, Progress Reports UNESCO Paris, France.