Wet Acid Digestion Method Research Articles

Assessment of Zinc, Lead, Chromium, and Cobalt in Commonly Consumed Herbal Medicines in Sindh, Pakistan.

Herbal medicines are widely consumed by the people of Pakistan for the treatment of various diseases. In the current study, quantitative assessment of four heavy metals namely zinc, lead, chromium, and cobalt was carried out in forty commonly consumed herbal medicines purchased from the markets of Khairpur and Sukkur, Pakistan. The conventional wet acid digestion method was used for the dissolution of samples and the concentration of heavy metals was determined by using flame atomic absorption spectrometry. Varied concentrations of metals were observed in different herbal medicines. The levels of Zn, Pb, Cr, and Co were in the range of 7.05-87.5 ppm, 5.62-44.9 ppm, 3.16-14.1 ppm, and 5.69-9.88 ppm, respectively. The findings of our study were compared with the WHO maximum permissible limits of these metals and it was observed that most of the analyzed samples exceeded the permissible levels. Keeping in view the levels of these metals in the selected herbal medicines, the prolonged intake of these drugs might be hazardous for human beings.

Antioxidant, phytochemical and physicochemical properties of sesame seed (Sesamum indicum L)

Objective: The aim of this study was to examine the antioxidant, phytochemical and physicochemical properties of sesame seeds grown in Ghana. Methodology: The seeds were extracted in either 70% (v/v) methanol, ethanol or acetone. The antioxidant activity of each extract was investigated using the DPPH, ABTS and FRAP assays. The total phenolic and total flavonoid contents were also investigated. The proximate analysis, as well as the mineral contents of the seeds, were carried out using the wet acid digestion method for multiple nutrient determinations. Results: The acetone extract demonstrated the highest antioxidant activity by scavenging 60.12 % DPPH, 96.45 % ABTS and had a FRAP value of 0.408. This was followed by the ethanolic extract, which quenched 55 % DPPH, 91.91 % ABTS, with a FRAP value of 0.245. The methanolic extract demonstrated the least antioxidant effect by scavenging 51.26 % DPPH, 89.72% ABTS and had a FRAP value of 0.208. The total Phenolic contents strongly correlated with antioxidant activity and were recorded at 99.67, 95.6 and 81.72 GAE/10 µL respectively for the acetone, methanolic and ethanolic extracts. The fat content of the seed was very high, constituting 56.56%. This was followed by carbohydrate (18.44 %), protein (15.67 %) and fibre (8.22%) with low moisture (3.49 %). Magnesium was found to be the mineral with the highest composition (182.47 mg/100g), which was followed by sodium (105.52), iron (7.37) and zinc (4.47) mg/100g. Conclusion: Sesame seeds possess significant antioxidant activity. They also contain significant amounts of phenolics, flavonoids, nutrients and minerals. This suggests that dietary uptake of sesame seeds could be potentially protective against diverse diseases.

Simultaneous determination of Fe and Ni in guarana (Paullinia cupana Kunth) by HR-CS GF AAS: Comparison of direct solid analysis and wet acid digestion procedures

Direct solid sampling method was compared with the conventional wet acid digestion method to simultaneously assay iron and nickel in guarana by high-resolution continuum source graphite furnace atomic absorption spectrometry. Measurements were done with the secondary lines of Fe and Ni. Four digestion procedures using mixtures of HNO3 and H2O2 (procedure A), HNO3 and HCl (procedure B), HNO3, HCl and H2O2 (procedure C) and HNO3, H2SO4 and H2O2 (procedure D) were evaluated. All tested procedures provided quantitative recoveries for Ni, whereas a good recovery for Fe was obtained only with procedure D. Procedure D was chosen for the digestion of all guarana samples. The limit of detection for the direct solid sampling method was 1.004 μg g−1 for Fe and 0.022 μg g−1 for Ni, and the precision ranged from 3.5–20.0% and 2.8–8.0% for Fe and Ni, respectively. Method accuracy was evaluated by statistical comparison between analyte concentrations, obtained by measurements in the solid samples by the proposed method and after the digestion of the samples by procedure D. The validation of the analytical results obtained for the solid and the digested sample was performed by Energy Dispersive X-Ray Fluorescence.

Evaluation of Toxic and Essential Metals in Some Selected Chewing Food Products and their Daily Intake by the Population of Karachi, Pakistan

The present study focused on different brands of chewing food products which containing some toxic metals (TMs) and essential metals and these samples were analyzed to determine the levels of some toxic metals (Pb, Cd, Ni, Cr and Mn) and essential metals (Ca, Cu, Fe, K, Mg, Na and Zn). The samples of gutka (100), sweet supari (63), sweet paan (16) and paan masala (21) were randomly collected from different shops of Karachi, Pakistan. The validity of conventional wet acid digestion method (CAD) was assessed by analyzing two certified reference materials (CRM) Virgina tobacco leaf (CTA-VTL-2) and Bovine liver (1577b) and standard addition recovery test. The limit of detections (LODs, n=10) of the method were found to be 0.144, 14.4, 8.89, 2.76, 4.06, 15.3 and 2.99, 22.9, 9.97, 4.54, 1.89, 1.76 µg L -1 for Ca, Cu, Fe, K, Mg, Na, Zn, Cd, Cr, Mn, Ni and Pb, respectively. The CAD method was successfully applied to real samples for the determination of toxic and essential metals.

Chemical and sensory properties of complementary food produced from sorghum (Sorghum bicolor l), pigeon pea (Cajanus cajan) and carrot (Daucus carrota) blends

The work was designed to develop a complementary food from sorghum, pigeon pea and carrot flour blends. The proximate and vitamin content of the samples were determined using standard AOAC methods. Mineral elements were determined using wet-acid digestion method for multiple nutrients determination. Means and standard deviation were calculated and compared using ANOVA. The chemicals and sensory properties were compared to those of cerelac. Ccerelac had significantly (p<0.05) higher protein (5.31%) and fat (3.93%). Sorghum:Pigeon pea:Carrot (50:20:30) had significantly higher fiber (0.17%) and ash (1.08%) while Sorghum:Pigeon pea:Carrot (50:30:20) was significantly higher in carbohydrate and energy (27.25g/100g and 159kcal/100g). Minerals of significant amounts in the products were P (213.22–216.86mg/100g), K(191.32– 194.63mg/100g), and Zn(88.8–93mcg/100g). β-carotene (7280mcg/100g) and vitamin C (4.78mg/100g) were significantly higher in S:P:C (50:20:30), while tecopherol (3.16mg/100g), riboflavin (0.29mg/100g), niacin (3.93mg/100g), pyrodixine (0.63mg/100g) and cyanocobalamin (0.24mg/100g). No phytochemical was detected in cerelac, in the blends all phytochemical assessed were below 1%. Sensory evaluation showed that cerelac was better accepted in terms of colour, texture, taste and flavor than the blends. Though the blends were not as acceptable as cerelac chemical test however showed that S:P:C (50:20:30) was richer in key nutrients such as β-carotene and vitamin C than cerelac.

Evaluation of chemical composition of candy developed from tigernut (Cyperus esculentus) milk

Tigernut (Cyperus esculentus) was bought from Amawusa Market in Umuahia town, Abia State. The seeds were purchased from five randomly selected vendors in the market and pooled to obtain the sample for analysis. Undamaged seeds were selected for the production of the candy. Tiger nut seeds (800g) were soaked for 8 hours in potable water, and then ground in a ratio of 1liter of water to each 300gram of tiger nuts. The mixture was left to macerate for 10 minutes. The mixture was pressed and filtered using a muslin cloth. Standard method was used to prepare the candy. The proximate and vitamin content of the samples were also determined using standard AOAC methods. Mineral elements were determined using wet-acid digestion method for multiple nutrients determination. All tests were carried out in duplicates and the data generated were analysed using standard methods. The proximate result shows that tigernut candy contains crude protein (2.78%), crude fat (24.84%), and crude fiber (0.04%) respectively. The calcium, potassium, phosphorus and iron contents were found to be 64.54, 132.82, 50.54 and 4.49mg/100g. The β- carotene was 83.82µg/100g, while the vitamins E, B2 and B3 were found to be 2.08, 0.09 and 0.09mg/100g. The saponin and oxalate each was 0.24%. The study showed that candy produced from tigernut milk is a relatively good source of protein, fat, calcium, potassium, and iron. Fiber found on tiger nut candy is also an added value.

Evaluation of the chemical and sensory attributes of juice developed from cashew and jackfruit pulp

Ready to eat Jackfruits (Artocarpus heterophyllus) were harvested from Obingwa and Ubakala in Abia state; the cashew apples (Anacardium occidentale) were harvested from cashew plantation along Enugu-Port Harcourt road, Enugu state, Nigeria. Standard method was used to prepare the juices and their blends. The proximate and vitamin content of the samples were determined using standard AOAC methods. Mineral elements were determined using wet-acid digestion method for multiple nutrients determination. All tests were carried out in duplicates and the data generated were analysed using standard methods. The moisture content of jackfruit juice, cashew juice and their blends ranges from 90.6% to 92.2%, with cashew juice having the highest moisture (92.2%) value While, jackfruit juice had the least moisture value (90.6%). Crude protein, ash and total carbohydrate values (1.32%, 0.46%, and 7.06% respectively) were significantly higher in jackfruit juice. Energy values of the products ranged between 29kcal to 38kcal. Iron was generally low in all the products. Cashew juice is a richer source of vitamins β-carotene, vitamin C and vitamin E (2.35mcg/100g, 284.35mg/100g and 0.47mg/100g respectively), followed by cashew juice: jackfruit juice (70:30) blend (2.05mcg/100g, 234.54mg/100g) and 0.42mgmg/100g respectively). Vitamins C and E ranged between 125-284mg/100g. 0.38-0.49mg/100g respectively; with cashew juice having the highest vitamin C and E values (284mg/100g, 0.49mg/100g respectively). The major components of the products were moisture, carbohydrate and protein. It was noted that jackfruit juice added to cashew juice at different proportions increased the magnesium and iron values of the blends, but reduced the sodium values. The result also showed that making blends from cashew and jackfruit juices enhances acceptability of the products.

Levels of Heavy Metals in the Soil: Effects of Season, Agronomic Practice and Soil Geology

Heavy metals status of agricultural soils should be monitored in order to prevent soil-plant pollution. This study evaluates the effect of season, agronomic practice and soil mineral composition on the levels of some heavy metals (Pb, Mn, Ni, Fe, and Zn) in the arable and oil palm soils of three Farm Settlements in Ogun-State Southwest, Nigeria. Soil samples were collected in two consecutive seasons between 2010 and 2012 and digestion was carried out using Standard Wet Acid Digestion method. Total heavy metals in the digest were determined using Flame Atomic Absorption Spectrophotometer (FAAS). The total levels of heavy metals (in mg/kg) found in the sampled soils were as follows: in the rainy season Mn (28.4 - 34.2), Fe (1599.7 - 2013.2), Pb (11.0 - 16.9), Zn (100.5 - 112.9) and Ni (11.3 - 13.8) and in the dry season Mn (32.1 - 40.1), Fe (1701.4 - 2455.5), Pb (13.0 - 18.7), Zn (105.7 - 110.4) and Ni (15.5 - 16.3). Levels of the heavy metals found in the sampled soils were significantly lower (p < 0.05) than their permissible levels in agricultural soils. Although the levels of heavy metals determined in dry season were higher than those of the rainy season, the only seasonal difference was that of Fe in Sawonjo soil significant at p = 0.05. The level of heavy metals in oil palm soils was significantly higher than the level in arable soils (p < 0.05). At present, pollution level of heavy metals in the sampled soils is low and poses no environmental risk, yet, they have to be regularly monitored before they bio-accumulate into toxic. Government should therefore set up soil monitoring agency and provide irrigation facilities to encourage dry season farming.

Interaction between essential elements selenium and zinc with cadmium and mercury in samples from hypertensive patients.

The abnormal metabolism of metal ions plays an important role in health and disease conditions; hence, the studies about them have received much interest. The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), selenium (Se), and mercury (Hg) in biological samples (scalp hair, blood, and urine) of hypertensive patients (n = 257), residents of Hyderabad, Pakistan. For comparison purpose, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials and by the conventional wet acid digestion method. The recovery of all studied elements was found in the range of 96.4-99.1 % in certified reference materials. The results of this study showed that the mean values of Cd and Hg were significantly higher in scalp hair, blood, and urine samples of hypertensive patients than in referents (P < 0.001), whilst the concentrations of Zn and Se were lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and Se and the high exposure of toxic metals may be synergistic with risk factors associated with hypertension.

Distribution of Potassium, Calcium, Magnesium, and Sodium Levels in Biological Samples of Pakistani Hypertensive Patients and Control Subjects

The abnormal metabolism of metal ions plays an important role in health and disease conditions, and studies about them have been attracting significant interest. The aim of our study was to assess the essential minerals (calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na)) in biological samples (scalp hair, blood, urine) of 387 hypertensive males and females, age 30-60 years, in an urban population together with 439 non-hypertensive subjects of same age group and residential areas. The element concentrations were measured by means of an atomic absorption spectrophotometer after microwave-induced acid digestion. The validity and accuracy was checked by conventional wet acid digestion method and using certified reference materials. The overall recoveries of all elements were found in the range of 99.1-99.9% of certified values. The results indicated significantly lower levels of Ca, Mg, and K in the biological samples (blood and scalp hair) of hypertensive patients, when compared to controls of both genders. The level of Na was found to be high in biological samples of hypertensive patients as compared to controls. The deficiency of Ca, Mg, and K may be synergistic with risk factors associated with hypertension. These data present guidance to clinicians and other professionals who will be investigating the deficiency of essential micronutrients in biological samples (scalp hair and blood) of hypertensive patients.

Distribution of arsenic, cadmium, lead, and nickel levels in biological samples of Pakistani hypertensive patients and control subjects.

The abnormal metabolism of metal ions plays an important role in health and disease conditions, and studies about them have been attracting significant interest. The aim of our study was to assess the toxic elements arsenic (As), cadmium (Cd), nickel (Ni), and lead (Pb) in biological samples (scalp hair, blood, urine) of 387 hypertensive males and females, aged between 30 and 60 years, from an urban population together with 439 non-hypertensive subjects, of the same age group and residential areas. The element concentrations were measured by means of an electrothermal atomic absorption spectrophotometer after microwave-induced acid digestion. The validity and accuracy was checked by conventional wet acid digestion method and using certified reference materials. The overall recoveries of all elements were found in the range of 96.8 - 99.4% of certified values. The results indicated significantly higher levels of As, Cd, Ni, and Pb in the biological samples (scalp hair, blood and urine) of hypertensive patients, when related to controls of both genders. The high exposure of toxic elements may be synergistic with risk factors associated with hypertension. These data present guidance to clinicians and other professionals who will be investigating the toxicity of heavy elements in biological samples (scalp hair and blood) of hypertensive patients.

Evaluation of chromium and manganese in biological samples (scalp hair, blood and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients.

The consequence of trace elements deficiency has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between high concentrations of chromium (Cr) and manganese (Mn) in scalp hair, blood, and urine and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on 62 male HIV+ patients (HIV-1) from different cities of Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, or high fever). The biological samples (scalp hair, blood and urine) were collected from AIDS patients, and for comparative study 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by electrothermal atomic absorption spectrophotometry after microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and with the values obtained by conventional wet acid digestion method on the same CRMs. The results indicated significantly lower concentrations of Cr and Mn in the biological samples (scalp hair, blood, and urine) of male HIV-1 patients, compared with control subjects. It was observed that the lower levels of these trace elements may be predictors for secondary infections in HIV-1 patients. There was a significant decrease in mean values of Cr and Mn in whole blood and scalp hair, whilst higher concentrations were observed in urine samples of the three groups of AIDS patients as compared to a controlled healthy male group (p < 0.001). Low Cr and Mn levels may be due to increased Cr and Mn losses. These data present guidance to clinicians and other professional investigating deficiencies of Cr and Mn in biological samples of AIDS patients.

Efficiency of Extraction of Trace metals from Blood samples using Wet Digestion and Microwave Digestion Techniques

The efficiency of extraction of trace metals using conventional wet acid digestion method (CDM) and microwave induced acid digestion method (MWD) was determined by recovery experiments. The high percentage recoveries obtained from microwave induced acid digestion method make it to be a more efficient method than the conventional wet acid method. The conventional wet acid digestion method is time consuming while the MWD method saves time, less than four minutes are required to complete the digestion of the biological samples in this study.

Distribution of Copper, Iron, and Zinc in Biological Samples of Pakistani Hypertensive Patients and Referent Subjects of Different Age Groups

The abnormal metabolism of metal ions plays an important role in health and disease conditions, and studies about them have been attracting significant interest. The aim of our study was to assess the trace metals (copper (Cu), iron (Fe), and zinc (Zn)) in biological samples (scalp hair, blood, urine) of 387 hypertensive males and females, age range 30 - 60 years, from an urban population and 439 non-hypertensive subjects of same age group and residential areas. The element concentrations were measured by means of an atomic absorption spectrophotometer after microwave-induced acid digestion. The validity and accuracy was checked by conventional wet acid digestion method, using certified reference materials. The overall recoveries of all elements were found in the range of 95.2 - 98.7 % of certified values. The results indicated significantly lower levels of Cu, Fe, and Zn in the biological samples (blood and scalp hair) of hypertensive patients when compared to referents of both genders while the levels of these elements was found to be high in urine samples of hypertensive patients as compared to referents. The deficiency of Cu, Fe, and Zn may be synergistic with risk factors associated with hypertension. These data present guidance to clinicians and other professionals who will be investigating the deficiency of essential micronutrients in biological samples (scalp hair, serum, and blood) of hypertensive patients.

Evaluation of Status of Arsenic, Cadmium, Lead and Zinc Levels in Biological Samples of Normal and Arthritis Patients of Age Groups (46 - 60) and (61 - 75) Years

Arthritis is a chronic inflammatory disease resulting in inflammation of diarthrodial joints (particularly joints of hands, wrists, feet, knees, ankles, and shoulders), manifested by swelling and functional impairment. This study was designed to evaluate the levels of the toxic elements arsenic (As), cadmium (Cd), and lead (Pb) and correlate those with the essential trace element zinc (Zn) in biological samples (scalp hair, blood, and urine) of arthritis patients, in two age groups (46 - 60 and 61 - 75) of both genders. For comparison purposes all three biological samples were collected from gender- and age-matched non-arthritic subjects as referents. The As, Cd, and Pb in biological samples were analysed by electrothermal atomic absorption spectrometry, prior to microwave assisted acid digestion. The level of Zn was determined by flame atomic absorption spectrometry. The validity and accuracy of the methodology was checked by using Certified Reference Materials (CRM) from the Community Bureau of Reference (BCR) of the Commission of the European Community and with those values obtained by conventional wet acid digestion method on the same CRMs. The results of this study showed that the mean values of As, Cd, and Pb were higher in blood, scalp hair, and urine samples of arthritis patients as compared to those values obtained in age-matched referent subjects. The concentration of Zn was lower in the biological samples of rheumatoid arthritis patients of both genders with respect to non-arthritic subjects. The urinary levels of the elements studied were found to be higher in the arthritis patients than in the age-matched healthy referents (p < 0.001). An inverse correlation was observed between Zn and toxic elements in biological samples of arthritis patients (r = 0.612 - 0.754). Intake of certain antioxidant micronutrients, particularly a zinc supplement, may protect against the development of rheumatoid arthritis.

&#x0D; Evaluation of Chromium, Cobalt and Manganese in Biological Samples (Scalp Hair, Blood, and Urine) of Pakistani Viral Hepatitis (A–E) Patients and Controls

The aim of the present study was to compare the level of chromium (Cr), cobalt (Co), and manganese (Mn) in biological samples (blood, urine, and scalp hair) of patients suffering from different types of viral hepatitis (A, B, C, D, and E; n = 521) of both genders, ages ranging from 31 - 45 years. For comparative study, 255 age-matched control subjects of both genders residing in the same city were selected as referents. The digests of all biological samples were analysed for Cr, Co, and Mn by electrothermal atomic absorption spectrometry (ETAAS). The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and compared with those values obtained by conventional wet acid digestion method on same CRMs. The results of this study showed that the mean values of Cr, Co, and Mn were higher in blood and scalp hair samples of hepatitis patients than in age-matched control subjects. The urinary levels of these elements were found to be higher in the hepatitis patients than in the age-matched healthy controls (p <0.001). These results are consistent with literature-reported data, confirming that the overload of these trace elements can directly cause lipid peroxidation and eventually hepatic damage.

플라스틱 소재의 비소 함유량 분석에 관한 연구

연속흐름 수소화물 생성-유도결합 플라스마 원자 방출 분광기(FI-HG-ICP-AES) 이용하여 플라스틱 소재에 함유된 비소를 정량하기 위한 조건을 얻었다. 플라스틱 시료를 습식 산 분해 방법 및 마이크로파 산 분해 방법으로 전처리하여 시험 용액을 조제하였다. 인증표준물질(CRM)인 CRM-EC680k 및 CRM-EC681k를 사용하여 측정한 값과 인증값을 비교하여 분석 방법의 재현성 및 정확성을 확인하였다. 습식 산 분해 방법 및 마이크로파 산 분해 방법으로 전처리하여 FI-HG-ICP-AES로 측정한 결과 CRM-EC680k의 경우에는 4.1~4.3 mg/kg (인증값 <TEX>$4.1{\pm}0.5$</TEX> mg/kg)이고, CRM-EC681k의 경우에는 28.9~30.6 mg/kg (인증값 <TEX>$29.1{\pm}1.8$</TEX> mg/kg)이었다. Quantitative analytical condition for arsenic in plastic materials by the flow injection-hydride generation-inductively coupled plasma-atomic emission spectrometry was studied. The plastic samples were dissolved by wet-acid digestion method and microwave-acid digestion method. The reproducibility and accuracy in this method was verified using of certified reference materials(CRMs) CRM-EC680k and CRM-EC681k. The analyical results agrees with certified value within the range of uncertainty. The results of CRM-EC680k wer 4.1~4.3 mg/kg (certified value <TEX>$4.1{\pm}0.5$</TEX> mg/kg), and the results of CRM-EC681k were 28.9~30.6 mg/kg (certified value <TEX>$29.1{\pm}1.8$</TEX> mg/kg).

Interaction between essential trace and toxic elements in the scalp hair samples of smokers and alcohol user diabetics

In the present study, trace and toxic elements were determined in the Scalp Hair (SH) samples of patients diagnosed with diabetes mellitus (DM) who were smokers and habitual alcohol drinkers living in Dublin, Ireland. The concentrations of elements were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using Certified Reference Material (CRM) (NCS ZC 81002b) and by the conventional wet acid digestion method on the same CRM. The results of this study showed that the mean values of cadmium, copper, iron, nickel and lead were significantly higher (P < 0.001), in scalp hair samples of diabetic patients as compared to referents of both gender. While the smokers and alcohol drinker referents and DM patients have two to three time higher values of these elements than those subjects who were not smokers and teetotallers. The concentrations of zinc, chromium and manganese were lower in the scalp hair samples of diabetic patients as compared to referents. The deficiency of zinc, chromium and manganese, while the high exposure of cadmium, lead and nickel, as a result of cigarette smoking and alcohol consumption, may be synergistic with risk factors associated with diabetes.

A Comparison of Microwave and Conventional Wet Acid Digestion Method for the Determination of Mercury in Coal and Coal Ash

Mercury in coal and coal ash samples was determined by atomic fluorescence spectrometry after microwave digestion. The validity of the method was studied by spike recovery tests and by analyzing certified reference material. The results obtained for mercury in coal and coal ashes were generally in good agreement with that of the wet digestion method. Moreover, microwave methods generally permitted to reduce considerably the digestion time. Furthermore, the mercury results obtained for coal samples by different acid mixtures microwave method provided valuable information for identifying the modes of occurrence of mercury in coal.

Interaction Between Zinc, Cadmium, and Lead in Scalp Hair Samples of Pakistani and Irish Smokers Rheumatoid Arthritis Subjects in Relation to Controls

The incidence of rheumatoid arthritis (RA) has been associated with cigarette smoking. The aim of our study was to assess the trace essential and toxic metals, cadmium (Cd), lead (Pb), and zinc (Zn), in scalp hair samples of 32 Irish and 46 Pakistani smokers and non-smokers RA male patients with age range 42-56 years. For comparison purpose, the scalp hair samples of 27 Irish and 55 Pakistani non-RA male subjects of the same age group were collected. The concentrations of trace and toxic elements were measured by inductive coupled plasma atomic emission spectrophotometer and atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials and using conventional wet acid digestion method on the same certified reference materials (CRMs). The recovery of all studied elements was found to be in the range of 97.5-99.7% of certified reference values of CRMs. The results of this study showed that the mean values of Cd and Pb were significantly higher in scalp hair samples of both smoker and non-smoker RA patients than in referents (P < 0.001), whereas the concentration of Zn was lower in the scalp hair samples of smokers and non-smokers rheumatoid arthritis patients. The deficiency of Zn and the high exposure of Cd and Pb as a result of cigarette smoking may be synergistic risk factors associated with rheumatoid arthritis.