A perylene diimide electrochemical probe with persulfate as a signal enhancer for dopamine sensing.

Dopamine (DA) is an important biomarker related to parkinsonism, schizophrenia and renal disease. Traditional electrochemical sensors for DA were based on the direct electrochemical oxidation of DA. In this paper, we report a new sensing strategy using N,N'-di(trimethylaminoethyl)perylene diimide (TMPDI) as an electrochemical probe and K2S2O8 as a signal enhancer for DA detection between 0 and -0.7 V with the DPV technique. MoS2 nanoflowers prepared by the hydrothermal method were used as a nanocarrier to load TMPDI. The reduction current of TMPDI was found to show a stepwise and significant increase at -0.24 V with the increase of concentration of K2S2O8 due to the continuous cycle of TMPDI molecules' electrochemical reduction and chemical oxidation. The presence of DA caused a large decrease of the reduction current of TMPDI due to the synergistic interaction of the competitive consumption of DA for K2S2O8 and the blocking effect of polyDA adhering to the electrode surface. The decreased current exhibited a linear response for DA from 10 pM to 100 µM with a detection limit of 4.1 pM and the proposed sensor showed high selectivity and excellent feasibility in human urine/serum sample detection.

Mono-/Bimetallic Neutral Iridium(III) Complexes Bearing Diketopyrrolopyrrole-Substituted N-Heterocyclic Carbene Ligands: Synthesis and Photophysics.

The synthesis and photophysics (UV-vis absorption, emission, and transient absorption) of four neutral heteroleptic cyclometalated iridium(III) complexes (Ir-1-Ir-4) incorporating thiophene/selenophene-diketopyrrolopyrrole (DPP)-substituted N-heterocyclic carbene (NHC) ancillary ligands are reported. The effects of thiophene versus selenophene substitution on DPP and bis- versus monoiridium(III) complexation on the photophysics of these complexes were systematically investigated via spectroscopic techniques and density functional theory calculations. All complexes exhibited strong vibronically resolved absorption in the regions of 500-700 nm and fluorescence at 600-770 nm, and both are predominantly originated from the DPP-NHC ligand. Complexation induced a pronounced red shift of this low-energy absorption band and the fluorescence band with respect to their corresponding ligands due to the improved planarity and extended π-conjugation in the DPP-NHC ligand. Replacing the thiophene units by selenophenes and/or biscomplexation led to the red-shifted absorption and fluorescence spectra, accompanied by the reduced fluorescence lifetime and quantum yield and enhanced population of the triplet excited states, as reflected by the stronger triplet excited-state absorption and singlet oxygen generation.

Selenium in cereals: Insight into species of the element from total amount.

Selenium (Se) is a trace mineral micronutrient essential for human health. The diet is the main source of Se intake. Se-deficiency is associated with many diseases, and up to 1 billion people suffer from Se-deficiency worldwide. Cereals are considered a good choice for Se intake due to their daily consumption as staple foods. Much attention has been paid to the contents of Se in cereals and other foods. Se-enriched cereals are produced by biofortification. Notably, the gap between the nutritional and toxic levels of Se is fairly narrow. The chemical structures of Se compounds, rather than their total contents, contribute to the bioavailability, bioactivity, and toxicity of Se. Organic Se species show better bioavailability, higher nutritional value, and less toxicity than inorganic species. In this paper, we reviewed the total content of Se in cereals, Se speciation methods, and the biological effects of Se species on human health. Selenomethionine (SeMet) is generally the most prevalent and important Se species in cereal grains. In conclusion, Se species should be considered in addition to the total Se content when evaluating the nutritional and toxic values of foods such as cereals.

Correlation between the level of microRNA expression in peripheral blood mononuclear cells and symptomatology in patients with generalized anxiety disorder.

This study investigated the correlation between the level of microRNA expression in peripheral blood mononuclear cells (PBMCs) and symptomatology in patients with generalized anxiety disorder (GAD). MicroRNA array was performed in peripheral blood mononuclear cells (PBMCs) obtained from GAD patients with gender, age, ethnicity-matched healthy controls. Then real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to verify the top 7 miRNAs with the highest fold-change values in 76 GAD patients and 39 healthy controls. It demonstrated that 5 miRNAs showed significantly differences in expression levels (P<0.01). These 5 GAD-associated miRNAs were finally selected into our study to analyze the association between the plasma level of miRNAs expression and symptomatology scores in Hamilton Anxiety Scale (HAMA). Results showed that the level of miR-4505 and miR-663 was negatively correlated with the total HAMA scores in GAD patients (r=0.2228, r=0.264 P<0.05). MiR-663 was selected into the regression equation of HAMA total scores and psychic anxiety symptomatology scores, and it could explain 5.3% of the HAMA total scores and 15.3% of the anxiety symptomatology scores. This study analyzed preliminarily possible circulating miRNAs expression changes in GAD patients, and the expression level of miR-663 highly correlated with psychic anxiety symptoms, further molecular mechanism of which needs to be explored.

Aberrant Expression of Long Non-Coding RNAs in Schizophrenia Patients.

BACKGROUND Dysfunction of long non-coding RNAs (lncRNAs) has been demonstrated to be involved in psychiatric diseases. However, the expression patterns and functions of the regulatory lncRNAs in schizophrenia (SZ) patients have rarely been systematically reported. MATERIAL AND METHODS The lncRNAs in peripheral blood mononuclear cells (PBMCs) were screened and compared between the SZ patients and demographically-matched healthy controls using microarray analysis, and then were validated by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) method. Three verified significantly dysregulated lncRNAs of PBMCs were selected and then measured in SZ patients before and after the antipsychotic treatment. SZ symptomatology improvement was measured by Positive And Negative Syndrome Scale (PANSS) scores. RESULTS One hundred and twenty-five lncRNAs were significantly differentially expressed in SZ patients compared with healthy controls, of which 62 were up-regulated and 63 were down-regulated. Concurrent with the significant decrease of the PANSS scores of patients after the treatment, the PBMC levels of lncRNA NONHSAT089447 and NONHSAT041499 were strikingly decreased (P<0.05). Down-regulation of PBMC expression of NONHSAT041499 was significantly correlated to the improvement of positive and activity symptoms of patients (r=-0.444 and -0.423, respectively, P<0.05, accounting for 16.9% and 15.1%, respectively), and was also significantly associated with better outcomes (odds ratio 2.325 for positive symptom and 12.340 for activity symptom). CONCLUSIONS LncRNA NONHSAT089447 and NONHSAT041499 might be involved in the pathogenesis and development of SZ, and the PBMC level of NONHSAT041499 is significantly associated with the treatment outcomes of SZ.

Long Non-Coding RNA: Potential Diagnostic and Therapeutic Biomarker for Major Depressive Disorder.

BACKGROUND The criteria for diagnosing depression are based on behavioral observation and self-reporting of symptoms by the patients or guardians without any biological validation of the disease. This study aimed to identify long non-coding RNAs (lncRNAs) in peripheral blood mononuclear cells (PBMCs) as robust and predictive biomarkers for diagnosis and therapy response in major depressive disorder (MDD). MATERIAL AND METHODS We used human lncRNA 3.0 microarray profiling (which covers 30,586 human lncRNAs), using PBMCs from five MDD patients and five controls. Differentially expressed lncRNAs in the PBMCs of MDD patients were identified, of which 10 candidate lncRNAs were selected for real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis in a larger cohort of 138 MDD patients and 63 healthy controls. Then among the 138 MDD patients who received standard antidepressant treatment, 30 were randomly selected for lncRNAs expression retesting and symptomatology assessments after three-weeks and six-weeks of antidepressant treatment. RESULTS Six lncRNAs (TCONS_00019174, ENST00000566208, NONHSAG045500, ENST00000517573, NONHSAT034045, and NONHSAT142707) were significantly downregulated in MDD patients compared to control patients, and the area under the receiver operator curve (ROC) of these six lncRNAs cases, combined, was 0.719 (95% confidence interval (CI): 0.617-0.821). There was no difference in the expression of these six lncRNAs based on gender (p>0.05) or age (p>0.05). CONCLUSIONS These results suggest that the combined expression of six lncRNAs in PBMCs may serve as a potential biomarker for diagnosis and therapy response of MDD in the clinical setting.

Psychological maladjustment of Asian and African peacekeepers in Liberia and its related factors.

This study aimed to investigate the maladjustment of Asian (Bangladeshi, Pakistani) and African (Nigerian, Namibian, Ghanaian) peacekeepers and its major influence factors. By random cluster sampling, 300 Asian peacekeepers and 271 African peacekeepers were administered the military psychological maladjustment scale (MPMS) and risk factors questionnaire. Investigation at Day 7 and Day 120 into the peacekeeping deployment period indicated that MPMS total score and factor scores of the Asian peacekeepers were significantly lower than those of the African peacekeepers (p < .01). The total score and each factor score of MPMS of the Asian peacekeepers significantly decreased (p < .01); for the African peacekeepers, only the factor score of emotional disorder of MPMS significantly decreased (p < .05). Stepwise regression analysis showed that the education duration was the influence factor for the emotional disorder factor score in the Asian peacekeepers, and the two factors were positively correlated. Age, military service duration, education duration and marital status were the major influence factors for the MPMS factors of the African peacekeepers, among which age was negatively correlated with the total score and each factor score, and military service duration, education duration and marital status were positively related. We conclude that the Asian peacekeepers are more adaptable and resilient than the African peacekeepers. Education duration was the major influence factor for Emotional Disorder in the Asian peacekeepers. The major influence factors for maladjustment in the African peacekeepers were age, military service duration, education duration and marital status.

A preliminary analysis of microRNA as potential clinical biomarker for schizophrenia.

MicroRNAs (miRNA, miR) have been implicated as promising blood-based biomarkers for schizophrenia patients. This study aimed to clinically validate miRNA as potential schizophrenia biomarkers. Plasma levels of 10 miRNAs were analyzed using qPCR in a cohort of 61 schizophrenia patients and 62 normal controls, as well as 25 patients particularly selected for a six-week antipsychotic treatment course. Positive And Negative Syndrome Scale (PANSS), Global Assessment Scale (GAS) and Clinical Global Impression (CGI) were administered to assess the clinical symptoms. The results demonstrated that a panel of miRNAs consisting of miR-30e, miR-181b, miR-34a, miR-346 and miR-7 had significantly increased expression levels with significant combined diagnostic value (AUC:0.713; sensitivity:35.5%; specificity:90.2%). In response to pharmacological treatment, expression levels of miR-132, miR-181b, miR-432 and miR-30e were significantly decreased. In addition, the improvement of clinical symptomatology was significantly correlated with the changes of miR-132, miR-181b, miR-212 and miR-30e expression levels. Furthermore, the decreases of plasma levels of miR-132 and miR-432 were significantly greater in high-effect subgroup than those in low-effect subgroup after six-week treatment course. We conclude that miR-30e, miR-181b, miR-34a, miR-346 and miR-7 combined as a panel are potentially useful non-invasive biomarkers for schizophrenia diagnosis. Markers miR-132, miR-181b, miR-30e and miR-432 are potential indicators for symptomatology improvements, treatment responses and prognosis for schizophrenia patients.

The transition-metal-catalyst-free oxidative homocoupling of organomanganese reagents prepared by the insertion of magnesium into organic halides in the presence of MnCl2·2LiCl.

Organomanganese reagents were prepared by the insertion of magnesium into aryl halides in the presence of MnCl2·2LiCl. These organomanganese reagents smoothly undergo 1,2-addition, acylation, and Pd-catalyzed cross-coupling with various electrophiles. Especially, the oxidative homocoupling of organomanganese reagents was completed in one pot without an additional transition-metal catalyst.

Psychosomatic conditions of the children and adolescents exposed to 5.12 Wenchuan earthquake.

BACKGROUND: A devastating earthquake registering 8.0 on the Richter Scale struck Wenchuan County in Northwest Sichuan Province in China on May 12, 2008, claiming over 69,200 lives, seriously wounding more than 374,600 people, and rendering more than 18,400 people missing. The epicenter was close to Yingxiu Township in Wenchuan County. PURPOSE: This study aimed to investigate the psychosomatic conditions of the children and adolescents exposed to the devastating earthquake and explore the risk factors for psychosomatic symptoms. METHOD: A total of 1,828 participants aged 6 to 16 years, of whom 842 from the affected area and 986 from non-affected area, were administered a Psychosomatic Conditions Scale. RESULTS: Each factor score, total somatic score, total psychological score, and total psychosomatic score of the experimental group were significantly higher than those of the control group (P < 0.001). Positive correlation was found between the psychological state and somatic symptoms in the experimental group(r = 0.157 ~ 0.489, P < 0.01). Respiratory system, cardiovascular system, nervous system, digestive system, urogenital system, emotion, behavior, and language, combined as a panel, were significantly differentiated between the two groups, accounting for 73.4% of the total difference. In the experimental group, the factor scores of anxiety, behavior, total psychological score, and total psychosomatic score of the girls were obviously higher than those of the boys (P < 0.01 ~ 0.05); most somatic factors and psychological factors, total somatic score, total psychological score, and total psychosomatic score of the elder adolescents were significantly higher than those of the younger children (P < 0.01 ~ 0.05). CONCLUSION: The children and adolescents exposed to 5.12 earthquake greatly suffered from terrible psychosomatic conditions, among whom the elder girls had more severe symptoms, particularly in terms of anxiety and behavior.

Determination of Aflatoxin B1 in Grains by Aptamer Affinity Column Enrichment and Purification Coupled with High Performance Liquid Chromatography Detection.

Aflatoxin B1 (AFB1) is a highly teratogenic and carcinogenic secondary metabolite produced by Aspergillus. It is commonly detected in agricultural products such as cereals, peanuts, corn, and feed. Grains have a complex composition. These complex components severely interfere with the effective extraction and separation of AFB1, and also cause problems such as matrix interference and instrument damage, thus posing a great challenge in the accurate analysis of AFB1. In this study, an aptamer affinity column for AFB1 analysis (AFB1-AAC) was prepared for the enrichment and purification of AFB1 from grain samples. AFB1-AAC with an AFB1-specific aptamer as the recognition element exhibited high affinity and specificity for AFB1. Grain samples were enriched and purified by AFB1-AAC, and subsequently analyzed by high performance liquid chromatography with post-column photochemical derivatization-fluorescence detection (HPLC-PCD-FLD). The average recoveries of AFB1 ranged from 88.7% to 99.1%, with relative standard deviations (RSDs) of 1.4-5.6% (n = 3) at the spiked levels of 5.0-20.0 µg kg-1. The limit of detection (LOD) for AFB1 (0.02 µg kg-1) was much below the maximum residue limits (MRLs) for AFB1. This novel method can be applied to the determination of AFB1 residues in peanut, corn, and rice.

Development of a Fast Method Using Inductively Coupled Plasma Mass Spectrometry Coupled with High-Performance Liquid Chromatography and Exploration of the Reduction Mechanism of Cr(VI) in Foods.

Hexavalent chromium (Cr(VI)) is known as the most hazardous species of chromium. Speciation analysis of Cr in foods is of a great significance for assessing its influences on human health. In this study, a fast HPLC-ICP-MS method for the determination of Cr(VI) was developed for determining the content of Cr(VI) and also investigating its transformation in foods. The developed method employs an alkali extraction and weak anion-exchange column separation for distinguishing the Cr species, facilitating accurate Cr(VI) quantification within 1.5 min. This technique was applied to determine the Cr(VI) levels in a range of food products, including yoghurt, milk powder, rice flour, orange juice, green tea, white vinegar, and whole wheat bread. The results showed that no Cr(VI) was detected in these food products. Spiking experiments revealed that the recovery rate of Cr(VI) decreased with the increase in its contact time with food products. A further exploration of Cr(VI) in various food components such as vitamin C, tea polyphenols, whey proteins, gelatin, fructose, and cellulose indicated the conversion of Cr(VI) to organic Cr(III) over a period from 20 min to 60 h. It was found that high temperatures and acidic conditions accelerated the rate of Cr(VI) conversion to organic Cr(III) in the six food components mentioned above. This evidence suggests that natural reducing substances in foods probably prevent the occurrence of Cr(VI).

Effects of allicin on growth performance, antioxidant profile, and microbiota compared to monensin of growing goats.

Allicin is a sulfur-containing compound extracted from raw garlic (Allium sativum L.). We compared the effect of allicin addition on growth performance, serum biochemical parameters, and rumen microbiota of goats compared to monensin. Twenty-four Anhui white goats were assigned randomly to one of three dietary treatments: 1) a basal diet (CON); 2) the basal diet with allicin addition at 750 mg per head per day (AC); 3) the basal diet with monensin addition at 30 mg per kg of diet (MS). Animals were fed for 8 weeks. Results showed the average daily gain, and feed efficiency was increased with allicin and monensin addition. Serum levels of IgG, total superoxide dismutase, and glutathione peroxidase were higher in the AC group than those in the CON and MS groups. The microbiota analysis revealed that monensin addition mainly affected genera related to carbohydrate and protein metabolism, and allicin mainly affected genera related to energy metabolism and intestinal health. In conclusion, allicin could improve growth performance and have advantages over monensin in improving the antioxidant capacity and immune function of goats. Allicin may be a potential alternative to monensin.

Nano­selenium functionalized chitosan gel beads for Hg(II) removal from apple juice.

The presence of potentially toxic elements and compounds poses threats to the quality and safety of fruit juices. Among these, Hg(II) is considered as one of the most poisonous heavy metals to human health. Traditional chitosan-based and selenide-based adsorbents face challenges such as poor adsorption capacity and inconvenient separation in juice applications. In this study, we prepared nano­selenium functionalized chitosan gel beads (nanoSe@CBs) and illustrated the synergistic promotions between chitosan and nanoSe in removing Hg(II) from apple juice. The preparation conditions, adsorption behaviors, and adsorption mechanism of nanoSe@CBs were systematically investigated. The results revealed that the adsorption process was primarily controlled by chemical adsorption. At the 0.1 % dosage, the adsorbent exhibited high uptake, and the maximum adsorption capacity from the Langmuir isotherm model could reach 376.5 mg/g at room temperature. The adsorbent maintained high adsorption efficiency (> 90 %) across a wide range of Hg(II) concentrations (0.01 to 10 mg/L) and was unaffected by organic acids present in apple juice. Additionally, nanoSe@CBs showed negligible effects on the quality of apple juice. Overall, nanoSe@CBs open up possibilities to be used as a safe, low-cost and highly-efficient adsorbent for the removal of Hg(II) from juices and other liquid foods.

The effects of wheat cultivar, flour particle size and bran content on the rheology and microstructure of dough and the texture of whole wheat breads and noodles.

The rheological properties and microstructure of doughs, and the texture properties of whole wheat breads and noodles were investigated. The gluten strength of doughs were discriminated due to wheat cultivar. Reduced flour particle size led to the doughs with a stronger gluten strength (i.e., smaller C2), lower degree of starch retrogradation (i.e., smaller C5), and longer relaxation time (i.e., larger n values). Firmer crumb of breads were prepared by flours with smaller particle size. With increased bran content, the gluten strength of dough weakened (i.e., increased C2), the development and relaxation time of dough and the degree of starch retrogradation decreased (i.e., decreased C1 time, n values and C5), the dough structure became more porous, and the product texture appeared to be firmer. As such, outcomes from this research will provide a practical guidance for the bakery industry to improve the consumer acceptability of whole wheat products.

Juglans mandshurica Maximowicz as a traditional medicine: review of its phytochemistry and pharmacological activity in East Asia.

OBJECTIVES: The conducted search reveals that Juglans mandshurica Maximowicz, called Manchuria walnuts, had many local uses that can be categorized into cancer, dermatosis and acesodyne. KEY FINDINGS: Various metabolites including diarylheptanoids, naphthoquinones, and flavonoids (also their glycosides) were reported as bioactive metabolites. The isolated metabolites and extracts from J. mandshurica showed different biological activity including cytotoxicity, anti-inflammation, antimelanotic, anticomplement, anti-HIV, antimicrobial and anti-obesity activity. SUMMARY: It is indicated that this review will add value to more scientific research on J. mandshurica and enhance the increased interest in the sustainable commercialization of J. mandshurica. It also leads to the validation of unverified ethnobotanical claims. Future studies on J. mandshurica would be focused to establish the links between the pharmacological activity, bioactive metabolites, and traditional uses.

Effect of gluconic acid rinsing on cadmium decontamination from rice protein.

Cadmium (Cd) accumulation in rice protein has long been considered a significant threat to human health. In the present study, a costless and effective method based on gluconic acid (GA) rinsing of rice protein was developed to reduce Cd contamination in rice protein. Moreover, the effect of GA on the structural and functional properties of rice protein was evaluated. With liquid-solid ratio of 30 mL/g and oscillation time of 120 min, 96.0% and 93.6% of Cd were eliminated from rice protein-H and rice protein-L, respectively. In addition, the results of scanning electron microscopy, Fourier transform infrared, and sodium dodecyl sulfate polyacrylamide gel electrophoresis analyses showed that GA treatment did not significantly change the structural properties of rice protein. However, GA treatment increased foaming properties, water holding capacity, and oil holding capacity of the rice protein, without affecting its further applicability. Thus, the proposed GA rinsing method can be considered a green and efficient strategy to solve the issue brought by Cd residual contamination in rice protein. PRACTICAL APPLICATION: Given the advantages of green and efficient agriculture, gluconic acid (GA) has emerged as a powerful strategy for removing the Cd from rice protein. The method developed herein showed great potentials for applications in the manufacture of rice-based products.

Facile synthesis of chitosan-tartaric acid biosorbents for removal of Cu(II) and Cd(II) from water and tea beverages.

Consumption of water and tea beverages leads to the intake of heavy metals by humans. Development of technology for decontamination greatly reduces the risks of the heavy metal exposure. In this study, environment-friendly chitosan-tartaric acid biosorbents (CTBs) were synthesized by a facile one-step cross-linking strategy to mitigate the Cu(II) and Cd(II) contamination in water and tea beverages. The cross linkage of tartaric acid and chitosan endowed CTBs with excellent properties in aspects of surface roughness, mechanical strength, and acid resistance. Adsorption performance and mechanism of CTBs were studied, and the Langmuir isotherm model and pseudo-second-order kinetic model were adhered during adsorption. Up to 90 % removal efficiencies of Cu(II) and Cd(II) from water and tea beverages by CTBs were achieved. Moreover, the adsorption showed only a slight reduction in the quality of tea beverages. This study offers a new insight for reduction of heavy metals-pollution in beverages.

New insights into the persistent effect of transient cinnamaldehyde vapor treatment on the growth and aflatoxin synthesis of Aspergillus flavus.

The antimicrobial effects of continuous treatment with essential oils (EOs) in both liquid and gaseous phases have been intensively studied. Due to their rapid volatility, the effects of EOs on microorganisms after transient treatment are also worth exploring. In this work, the persistent effects of cinnamaldehyde (CA) vapor on Aspergillus flavus were detected by a series of biochemical analyses. Transcriptome analysis was also conducted to study the gene expression changes between recovered and normal A. flavus. When CA vapor was removed, biochemical analyses showed that the oxidative stress induced by the antimicrobial atmosphere was alleviated, and almost all the damaged functions were restored apart from mitochondrial function. Remarkably, the suppressed aflatoxin production intensified, which was confirmed by the up-regulation of most genes in the aflatoxin synthetic gene cluster, the velvet-related gene FluG and the aflatoxin precursor acetyl-CoA. Transcriptomic analysis also demonstrated significant changes in secondary metabolism, energy metabolism, oxidative stress, and amino acid metabolism in the recovery group. Taken together, these findings provide new insights into the mechanisms underlying the response of A. flavus to CA vapor treatment and will guide the rational application of EOs.

Beer-derived nitrogen, phosphorus co-doped carbon quantum dots: Highly selective on-off-on fluorescent probes for the detection of ascorbic acid in fruits.

A rapid, facile and ultrasensitive fluorescence sensing system based on beer-derived nitrogen, phosphorus co-doped carbon quantum dots (N, P-CQDs) for the detection of ascorbic acid (AA) in fruits was proposed. N, P-CQDs were successfully synthesized by one-step hydrothermal method, which afforded a high quantum yield (21.7 %), and showed the fluorescence with a maximum emission wavelength of 450 nm at an excitation wavelength of 370 nm. Further, N, P-CQDs were employed as an efficient sensor for ultrasensitive Fe3+-detection at concentrations ranging from 1-20 µM and 100-300 µM, respectively. N, P-CQDs@Fe3+ showed a high sensitivity and selectivity for AA detection. A linear response range for AA was obtained from 1 to 200 µM with limit of detection of 0.84 µM was obtained for AA. The result of MTT test showed that N, P-CQDs exhibit low toxicity, providing fast, accurate and less toxic route for testing AA in the food analysis fields.