Application of instrumental neutron activation analysis to plant medicines in Ghana: A review

Some essential elements in eleven plant medicines used at the Center for Scientific Research into Plant Medicine (CSRPM), Mampong-Akwapim, Ghana, for the management and cure of various diseases were determined by instrumental neutron activation analysis (INAA), using thermal neutrons at a flux of 5^.10¹¹ n^.s^-1.cm^-2. The plant medicines were: Sirappac powder-E, Tina-A powder, Blighia powder, Aphrodisiac powder, Ninga powder and Lippia tea. The others are Olax powder, Ritchiea powder, Momordica powder, Kenken and Fefe powder. Concentrations of seventeen elements namely Al, Br, Ca, Cl, Co, Cu, Cr, K, Mn, Mg, Na, Rb, Sb, Sc, Ta, V, and Zn have been determined by short, medium and long irradiation times. Of these elements Co, Sb, and Sc are found to be present at the trace level, Br, Cu, Cr, Mn, Rb, Ta, V and Zn at the minor level, while Al, Ca, Cl, K, Mg and Na were generally at major level. The differences in the concentration of the elements are attributed mainly to soil composition and climate in which the plants grow. Standard reference material NIST SRM-1571 (Orchard Leaf) was analyzed simultaneously with the samples. The precision and accuracy of the method were evaluated using real samples and the standard reference material. It was found that the elemental concentrations measured in the NIST SRM-1571 were within ±10% of the reported values. The importance of these elements as related to human health and nutrition has been discussed.     

Trace element content of medicinal plants from Algeria

Neutron activation analysis (INAA) has been applied to multielemental determination of eleven medicinal plants used to cure the urinary tract diseases observed in Algeria. These plants include Androgena Citratus, Ceratonia Siliquata, Punica Granatum, Glyryrrhiza Glabra, Lausaunia Alba, Fragaria Vesca, Arbutus Unedol, Hordeum Vulgaris, Papieteria Officinalis, Zea Mays L, and Davallia Seae. Concentrations of twenty elements Ba, Br, Ca, Cl, Co, Cu, Cr, Fe, I, Mn, Na, Mg, Rb, Sb, Se, Sc, Sr, Ti, V, and Zn have been determined by short, and long irradiation times with a thermal and epithermal flux of 1.4·10¹² n·cm⁻²·s⁻¹ and 1.4·10¹¹ n·cm⁻²·s⁻¹, respectively. These analyses were performed in conjunction with Compton suppression. In almost herbs studied the Co, Cr, Cu, Rb, Sb, Sc, Se and V are found to be present at trace levels, Br, Mn, and Zn at the minor level, and Ca, Cl, Fe, Mg and Na are generally at the major level. The accuracy of the measurements has been evaluated by analyzing NIST-botanical references materials.     

Chemical characterization of graphite by instrumental neutron activation analysis

Nuclear and commercial grade graphite samples were analysed by instrumental neutron activation analysis (INAA) using high flux reactor neutrons. Eleven elements (Na, K, As, Sc, Fe, Cr, Co, Zn, La, Ce, and Sm) were determined in eight samples of graphite (two nuclear grade and six commercial grade) by irradiating at a neutron flux of 3?×?10¹³ cm^?2 s^?1 in CIRUS reactor and assaying the activity by high-resolution gamma ray spectrometry using 40% relative efficiency HPGe detector coupled to an MCA. Concentrations of elements were determined by relative method of INAA. Results of both types of graphites as well as detection limits achieved by INAA method are discussed in the paper.     

Multi-element analysis of blood for trace metals by neutron activation analysis

Fourteen elements can be rapidly determined in whole blood by the neutron activation analysis procedure described. Three of these (Ag, Cl, Se) are measured after a 10-s irradiation and eleven others (Al, Ba, Br, Ca, Cu, I, Mg, Mn, Mo, Rb, V) are determined by a 180-s irradiation of a 1-cm³ sample of whole blood after destruction of organic matter and removal of sodium by hydrated antimony pentoxide. A further 13 elements (As, Au, Co, Cr, Cs, Fe, Hg, K, Na, Ni, Sb, Sc, Zn) are determined after overnight irradiation in the SLOWPOKE reactor.     

Trace element impurity determination in aspirin tablets by INAA

Instrumental neutron activation analysis (INAA) was applied to assess trace element concentrations in six samples of aspirin tablets acquired in São Paulo city, Brazil. Concentrations of the elements Br, Ca, Co, Cr, Fe, K, La, Na, Sc and Zn were determined. Comparisons were made between the results obtained with published data for aspirins from foreign countries. Certified reference materials, INCT-MPH-2 Mixed Polish Herbs were analyzed for quality control of the analytical results.     

Preliminary study of trace elements in human brain tumor tissues by instrumental neutron activation analysis

Elemental profiles of brain tumor tissues from 15 patients of astrocytomas (grade I–III) and normal human brain tissues of 23 male age matched autopsies as controls have been studied by instrumental neutron activation analysis. The SLOWPOKE reactor with a thermal neutron flux of 8·10¹¹n·cm^–2·s^–1 and swimming pool type reactor with a thermal neutron flux of 1·10¹³n·cm^–2·s^–1 were used for short and long irradiation of samples, respectively. Spectrophotometry was only used for analyzing phosphorus. A total of 18 elements Se, Na, K, Br, Cl, Mn, Mg, S, Ca, Cu, Hg, Cr, Fe, Rb, Zn, Co, Sc and P has been determined for this purpose. The reliability of methods has been checked by analyzing biological standard reference materials horse kidney (IAEA H-8) and bovine liver (NBS SRM 1577a). The analytical results showed that compared with the normal brain tissues, concentrations of Ca, Fe, Cu, Zn, Se, Mn, Br and Sc were significantly higher in tumor tissues (P<0.01) and concentrations of Rb, K and P were lower, while no differences for contents of Mg, S, Cr, Hg, Na and Cl were observed. A negative correlation between P and Ca in malignant and normal brain tissues was observed.     

Quality assessment of organic coffee beans for the preparation of a candidate reference material

Summary A random sampling was carried out in the coffee beans collected for the preparation of the organic green coffee reference material in view of assessing the homogeneity and the presence of soil as impurity. Fifteen samples were taken for the between-sample homogeneity evaluation. One of the samples was selected and 10 test portions withdrawn for the within-sample homogeneity evaluation. Br, Ca, Co, Cs, Fe, K, Na, Rb, Sc and Zn were determined by instrumental neutron activation analysis (INAA). The F-test demonstrated that the material is homogeneous for Ca, Co, Cs, K and Sc, but not homogeneous for Br, Fe, Na, Rb and Zn. Results of terrigenous elements suggested negligible soil contamination in the raw material.     

Synthetic multielement standard samples for serial neutron activation analysis of biological materials

New synthetic standard samples (SSB-1 and SSB-2), produced on the basis of phenol-formaldehyde resin in the shape of tablets are suggested. The samples are intended for INAA of biological materials. SSB-1 and SSB-2 samples contain Se, Cr, Au, Sb, Ag, Rb, Fe, Zn, Co and Ca, Ba, Hg, Sn, Br, Cs, Ni, Sc and Na. The concentrations of these elements are chosen so that the maximum statistical error of -quantum registration by the semiconductor detector should not exceed 3% when irradiating samples in a neutron flux of 10¹³ n·cm^–2·s^–1.     

A study of the elemental composition of diabases by instrumental neutron activation and X-ray fluorescence analysis

The distribution of the elemental composition was studied mainly for microelements in the diabases of the Pechenga suite subjected to various changes. Investigations were conducted by a combination of instrumental neutron activation INAA and X-ray fluoresence XRFA analyses. The INAA was conducted with sample weights of 20–100 mg exposed to irradiation in a nuclear reactor by a flux of neutrons ≈10¹³ n·cm⁻²·s⁻¹. Measurements were carried out by means of a semi-conductor gamma-spectrometer with a Ge(Li) detector. The determination of Al, Mn, Mg, Ti, V, Ca was conducted by short-lived isotopes, while the determination of Na, Sc, Fe, Co, Cr, Hf, Th, La, Ce, Sm, Eu, Yb, Lu by longlived ones. For XRFA samples weighing up to 2 g were irradiated by means of an¹⁰⁹Cd isotope source and were measured by a spectrometer with a Si(Li) detector and beryllium window. By this method we determined the Sr, Zr an Nb contents. Continuous distribution histograms were plotted for the concentration of 22 elements and some of their ratios. Considerable variations in microelemental composition observed in a number of cases make it possible to assess the character of past processes of diabasic change.     

INAA of IAEA-331 (spinach), SRM,for 40 elements

Forty elements in IAEA-331 (Spinach), an intercomparison material, have been determined using NAA. Among them, 30 elements, Ag, Al, Ba, Br, Ca, Ce, Cl, Co, Cr, Cs, Eu, Fe, Hf, K, La, Mg, Mn, Na, Ni, Rb, Re, Sc, Se, Sr, Ta, Tb, Th, V, Zn and Zr were determined by INAA. A series of simple and quantitative radiochemical separation procedures were established for the determination of ten additional elements. Cd, Lu, Mo, Sb, Sm, Yb, U were determined by removing the major interfering nuclide⁸²Br. Cu was determined by 0.048M NaDDTC/CHCl₃ extraction from 1M HCl medium. As and P were determined using an inorganic exchange column of acid aluminium oxide (AAO). Integral counts from 80 keV to 130 keV contributed by Bremsstrahlung from³²P -were used to evaluate the content of phosphorus.     

Elemental characterization of the new Czech meteorite ‘Morávka’ by neutron and photon activation analysis

Forty two major, minor and some trace elements were determined by activation analysis in the new Czech Morávka H5 chondrite, which fell on May 6, 2000 in the vicinity of Morávka, north-east Moravia. The elements Na, Mg, Al, Si, Cl, Ca, Ti, V, Mn, Co, Ni, and Cu were determined by means of instrumental short-time neutron activation analysis (INAA), whereas another group of elements, namely Sc, Cr, Fe, Co, Ni, Zn, As, Se, Br, Sb, La, Sm, Ir, Au and Hg were assayed using long-time INAA. Most of the rare earth elements (REE) were determined by radiochemical neutron activation analysis (RNAA) using precipitation of their oxalates, whilst for the determination of Rb and Cs an RNAA procedure based on selective sorption of the elements on ammonium phosphomolybdenate was employed. Mg, Ca, Ti, Mn, Ni, Sr, Y and Zr were determined by instrumental photon neutron activation analysis (IPAA) using the irradiation with 20 MeV bremsstrahlung from a microtron. For quality control, the U.S. Geological Survey (USGS) reference rocks basalt BCR-1 and diabase W-1 were analyzed. Moreover, the self-verification principle in activation analysis was employed to increase the credibility of the obtained results.     

Determination of trace elements in fish by instrumental neutron activation analysis

Instrumental neutron activation analysis, INAA, was utilized for the determination of Al, Au, Br, Ca, Cl, Co, Cr, Cu, Fe, I, K, Mg, Mn, Na, Rb, Sc, V and W in 12 Tilapia Nilotica samples collected from the Aswan High Dam Lake following the destructive techniques.     

A search for losses of chemical elements during freeze-drying of biological materials

Possible losses of seven chemical elements were investigated in biological tissues during freeze-drying in vacuum. Thyroid glands were taken during post-mortem examination of 23 people died of different diseases. Instrumental neutron activation analysis (INAA) was used to estimate contents of Br, Ca, Cl, I, K, Mg, and Na. The nuclear reator vertical channel with flux density of 1.2·10¹³n·cm^–2·s^–1 was used for neutron irradiation. The analysis was carried out using short-lived radionuclides induced in samples after neutron irradiation. Then thyroids were freeze-dried at below 0 °C in vaccum up to the constant mass (lyophilisation) and then homogenized. Samples of lyophilised and homogenized tissues were again studied by INAA. The lack of difference between the results of the analysis before and after lyophilisation is an evedence of no loss of Br, Ca, Cl, I, K, Mg and Na during freeze-drying of biotissues in vaccum.     

Determination of trace elements in food by neutron activation analysis

Neutron activation analysis (NAA) methods have been developed for the determination of major, minor and trace elements in duplicate diets and individual food items. These include a cyclic instrumental NAA (CINAA) method for measuring Se content through its short-lived nuclide^77mSe; epithermal INAA (EINAA) for I and As; conventional INAA for Br, Ca, Cl, Co, Cr, Fe, K, Mg, Mn, Na, Rb, Sb, Sc, Sn and Zn; combination of EINAA and INAA for Al; radiochemical NAA (RNAA) for As, Au, Co, Cu, Fe, Hg, Mo, Sb, Se and Zn; and preconcentration NAA (PNAA) for U and Th. Accuracy of measurements have been evaluated by analyzing a number of biological and diet reference materials. Multielement concentrations of diets and foods have been measured by these methods.     

INAA of some phosphates used in fertilizer industries

INAA method for As, Br, Ca, Ce, Co, Cr, Eu, Fe, K, La, Lu, Na, Nd, Sb, Sc, Sm, Tb, Th, U, Yb and Zn determination in raw phosphates and Romanian NPK phosphate fertilizers was applied. The concentration values of uranium and some possible toxic elements in fertilizers are discussed.     

The application of Westcott Formalism k0 NAA method to estimate short and medium lived elements in some Ghanaian herbal medicines complemented by AAS

The epithermal neutron shape factor, α of the inner and outer irradiation sites of the Ghana Research Reactor-1 (GHARR-1) was determined obtaining results of 0.105 for the inner (Channel 1) Irradiation site and 0.020 for the outer (channel 6) irradiation site. The neutron temperatures for the inner and outer irradiation sites were 27 °C and 20 °C, respectively. The α values used in Westcott Formalism k₀ INAA was applied to determine multi elements in 13 Ghanaian herbal medicines used by the Centre for Scientific Research into Plant Medicine (CSRPM) for the management of various diseases complemented by Atomic Absorption Spectrometry. They are namely Mist. Antiaris, Mist. Enterica, Mist. Morazia, Mist. Nibima, Mist. Modium, Mist. Ninger, Mist Sodenia, Mist. Tonica, Chardicca Powder, Fefe Powder, Olax Powder, Sirrapac powder and Lippia Tea. Concentrations of Al, As, Br, K, Cl, Cu, Mg, Mn, Na and V were determined by short and medium irradiations at a thermal neutron flux of 5×10¹¹ ncm⁻² s⁻¹. Fe, Cr, Pb, Co, Ni, Sn, Ca, Ba, Li and Sb were determined using Atomic Absorption Spectrometry (AAS). Ba, Cu, Li and V were present at trace levels whereas Al, Cl, Na, Ca were present at major levels. K, Br, Mg, Mn, Co, Ni, Fe and Sb were also present at minor levels. Arsenic was not detected in all samples. Standard Reference material, IAEA-V-10 Hay Powder was simultaneously analysed with samples. The precision and accuracy of the method using real samples and standard reference materials were evaluated and within ±10% of the reported value. Multivariate analytical techniques, such as cluster analysis (Q-mode and R-mode CA) and principal component analysis (PCA)/factor analysis (FA), have been applied to evaluate the chemical variations in the herbal medicine dataset. All the 13 samples may be grouped into 2 statistically significant clusters (liquid based and powdered herbal medicines), reflecting the different chemical compositions. R-mode CA and PCA suggest common sources for Co, Mg, Fe, Ca, Cr, Ni, Sn, Li and Sb and Na, V, Cl, Mn, Al, Br and K. The PCA/FA identified 3 dominant factors as responsible for the data structure, explaining 84.5% of the total variance in the dataset.     

Characterization of Brazilian commercial milks by instrumental neutron activation analysis

Aiming at the determination of toxic and essential elements in Brazilian commercial bovine milk, 25 ultra high temperature (UHT) milk samples were acquired in the local market of Piracicaba, SP. The samples were freeze-dried and analyzed by instrumental neutron activation analysis (INAA) allowing the determination of Br, Ca, Co, Cs, Fe, K, Na, Rb and Zn. When the results were expressed as concentration (mg·l⁻¹) no significant differences were found. However, considering the dry matter, results showed a clear difference between the mass fractions (mg·kg⁻¹ d.w.) of skim milk and whole milk for the elements Br, Ca, K, Na, Rb and Zn, indicating that the removal of fat caused a concentration effect in the dry matter of skim milks. Discrepancies were found between the concentrations of Ca and Na measured by INAA and the values informed in the labels. Ca showed variations within 30% for most samples, while concentrations of Na were up to 190% higher than informed values. The sample preparation and the INAA procedure were appropriate for the determination of Br, Ca, Co, Cs, Fe, K, Na, Rb and Zn in milk samples.     

Multielement investigation of human bile by means of instrumental neutron activation analysis

In a study on gold containing antirheumatic agents, the portion of gold that was eliminated via liver was quantified. Seven patients whose gall bladders had just been removed surgically received 5 tablets RIDAURA^® containing a total amount of 4.35 mg gold in the chemical compound Auranofin. In the following 7 days samples of hepatic bile were collected and analyzed by instrumental neutron activation analysis (INAA). After a 3-day irradiation with neutrons in the Research Reactor Geesthacht (FRG) and after a waiting time of 5–10 days, the limit of detection for gold was about 0.03 ng. The gold concentration in bile reached the maximum value (≈65 ng/ml) after about 16 hours and decreased with a biological half-life, first of 21 hours and later, in the end phase, of 6.5 days. Further elements were determined in the hepatic bile: Na, Ca, Fe, Co, Zn, Se, Br, Rb, Cs, Ba, Hg and sporadically K, Sc, Cr, Ni, Sb, La, Ce, Eu, Tb, Hf, Ta, Th. Some of these elements occurred in clusters. The blank values of the quartz ampoules and the precision, accuracy and limit of detection of these elements are given. The element concentrations found in bile are compared with those in plasma and classified after BRAUER.     

Neutron activation analysis of ivory of African elephants

Instrumental neutron activation analysis was applied to 61 ivory samples of which origin countries are known. 12 elements such as Br, Ca, Cl, Co, Cs, Fe, Mg, Mn, Na, Sc, Sr and Zn, were determined in all samples. The factor score of each sample was calculated for each factor by making use of principal component analysis in order to determine their origins. The results were compared with those by stable isotope analysis (¹³C and¹⁵N).     

A pilot study to measure levels of selected elements in Thai foods by instrumental neutron activation analysis

A pilot study was carried out to evaluate the scope of instrumental neutron activation analysis (INAA) for measuring the levels of selected elements in a few commonly consumed food items in Thailand. Several varieties of rice, beans, aquatic food items, vegetables and soybean products were bought from major distribution centers in Bangkok, Thailand. Samples were prepared according to the protocols prescribed by the nutritionist for food compositional analysis. Levels of As, Br, Ca, Cd, Cl, Cr, Cu, Fe, K, Mg, Mn, and Zn were measured by INAA using the irradiation and counting facilities available at the Thai Research Reactor with the maximum in-core thermal neutron flux of 3 × 10¹³ cm^?2 s^?1 of the Thailand Institute of Nuclear Technology in Bangkok. Selenium was determined by cyclic INAA using the Dalhousie University SLOWPOKE-2 Reactor facilities in Halifax, Canada at a thermal neutron flux of 2.5 × 10¹¹ cm^?2 s^?1. Both cooked and uncooked foods were analyzed. The elemental composition of food products was found to depend significantly on the raw material as well as the preparation technique.