Determination of arsenic speciation in 17 commonly used traditional Chinese herbal medicines by HPLC-ICP-MS / 中国中药杂志

The element speciation analysis for heavy metals in herbal medicines is still in the beginning stage. In this study,the total amount of arsenic( As) in 103 batches of 17 commonly used Chinese medicines( including 16 plant medicines and 1 medicinal fungus) was detected by inductively coupled plasma mass spectrometry( ICP-MS). Furthermore,based on HPLC-ICP-MS,the simultaneous detection methods of six As speciation kinds in traditional Chinese medicines were established. An AS7 anion exchange column was selected and the As forms in 17 traditional Chinese medicines was systematically analyzed. The results showed that the method of pretreatment of medicinal materials by microwave digestion and the detection of total amount of As by ICP-MS was stable and reliable. As for the speciation analysis of As,the high-speed ultrasonic extraction method was adopted,and it showed that the linear relationship of the six As speciation was satisfied with the correlation coefficient R2>0. 999 9. The LOQ of six kinds of As speciation were 0. 20,0. 10,0. 15,0. 10,0. 25,0. 10 μg·L~(-1) for arsenic betaine( As B),arsenious acid [As( Ⅲ) ],dimethyl arsenic( DMA),arsenic choline( As C),monomethyl arsenic( MMA),arsenic acid[As( Ⅴ) ],respectively. The recoveries were between 84. 24% and 121. 5%,and the relative standard deviations were 2. 7% to 11%. Among the 103 batches of medicinal materials,only one batch of sample As exceeded the Chinese Pharmacopoeia limit standard; As( Ⅲ) and As( Ⅴ) had high detection rate in 103 batches of Chinese herbal medicines,within which As( Ⅴ) was the main detected form,and inorganic As accounted for the ratio reached 80. 90%-98. 73%; some samples detected DMA,MMA and As B,As C was not detected in any batch. This study established an analytical method suitable for the speciation of As in Chinese herbal medicines,and provided basic data for As residual residue in Chinese herbal medicines,which can provide important reference for the risk assessment and quality standards.

Analysis of arsenic speciation in Sepiae Endoconcha and research on its limit standard / 中国中药杂志

Sepiae Endoconcha is a common marine animal medicine,which generally contains high concentration of arsenic( As).The Chinese Pharmacopoeia( 2010 edition,part I) stipulated that the total As content of Sepiae Endoconcha should not exceed 2 mg·kg~(-1),while this limit was revised to 10 mg·kg~(-1) in the 2015 edition. So far,there is no research on the speciation of As in Sepiae Endoconcha,which made it hard to accurately evaluate its security risk. In this study,32 batches of Sepiae Endoconcha from different sources were collected. The safety risk assessment was carried out by determining the total As content and As speciation,inorganic As[As( Ⅲ),As( Ⅴ) ]and organic As( MMA,DMA,As C,As B) by HPLC-ICP-MS,and then the limit standard was discussed. The results showed that As B was the main form of As in Sepiae Endoconcha,followed by DMA and As( Ⅴ) ． Of the 32 batches of Sepiae Endoconcha,9 batches( accounting for 28%) were detected possessing i As. The maximum concentration of As( Ⅲ) was 103. 3 μg·kg~(-1),and the maximum concentration of As( Ⅴ) was 222. 4 μg·kg~(-1). According to the limit of i As in food,18. 75% of the samples exceeded the standard. The results indicate that there is no simple positive correlation between total As and As morphology in Sepiae Endoconcha. Besides,there is a risk in the total As limit,especially after the relaxation of the total As limit. The problem of high i As content caused by pollution and other factors is difficult to regulate. Since the toxicity of inorganic As is much higher than that of organic As,it is of great practical significance to establish inorganic As form limits in Sepiae Endoconcha.

Arsenic speciation in rat plasma after oral administration of realgar and Niu Huang Jie Du Pian / 药学学报

The arsenic species in rat plasma were studied after oral administration of realgar and Niu Huang Jie Du Pian (NHJDP) and the possible compatible effects of realgar was evaluated by comparing the pharmacokinetics of arsenic species after administration of realgar and NHJDP. The separation of the arsenicals was performed by a high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS) technique. Dimethylarsinic acid (DMA) was found to be the main species in rats' plasma after dosing. No traces of arsenite[As(Ⅲ)], monomethylarsonic acid (MMA) or arsenate[As(V)] were detected at any sampling time points. Compared with realgar administration alone, dose-normalized peak concentration (Cmax) and AUC0-t of DMA were significantly decreased by NHJDP administration, while the tmax was significantly delayed with the clearance and apparent volume of distribution significantly increased, indicating that the pharmacokinetics of As from realgar was affected by other ingredients in the compound prescription of NHJDP.

Arsenic speciation of Niuhuang Jiedu Tablets in water and gastrointestinal fluids by HPLC-ICP-MS / 中国药学杂志

OBJECTIVE: To investigate the arsenic speciation of Niuhuang Jiedu Tablets (traditional Chinese medicines) in water and gastrointestinal fluids by HPLC-ICP-MS, so as to quantitatively evaluate the arsenical toxicity of Niuhuang Jiedu Tablets. METHODS: An HPLC-ICP-MS method for the determination of AsIII, AsV, MMA, DMA and the identification of AsB and AsC was established, and the arsenic speciation of Niuhuang Jiedu Tablets in water, gastric fluid, and intestinal fluid was determined and analyzed. RESULTS: The method validation indicated that the correlation coefficients (r) for As, As, MMA, and DMA were all over 0.9994, the limits of quantitation (LOQ) were between 0.66 and 1.19 μg · L-1, the precisions and stabilities were satisfactory with all RS-Ds less than 5%, and the spiked recoveries ranged from 92.78% to 100.2%. The results of samples analysis showed that only inorganic arsenic (As and As) and trace amount of unknown arsenic speciation were detected, while MMA, DMA, AsB, and AsC were not found in any cases; highly toxic inorganic arsenic (As and As) were dominating arsenic speciation of Niuhuang Jiedu Tablets in water and gastrointestinal fluids. CONCLUSION: This method could be used for the arsenic speciation analysis of Niuhuang Jiedu Tablets in water and gastrointestinal fluids.

Determination of As (III) and As (V) in grape juice samples by differential pulse cathodic stripping voltammetry

This study describes a simple and sensitive voltammetric method for determining As (III) and As (V)concentrations in ìg.L-1. Electroactive As (III) is evaluated by direct analysis. As (V) is converted into As (III) using reduction solution; the new As (III) concentration, represents the total inorganic As in the analyzed sample. As (III) and total inorganic As determination showed a work potential peak at -0.68 V;As (V) concentration was determined by subtraction [total inorganic As – As (III)]. Quantification and detection limits for As (III) were 0.22 and 0.08 ìg.L-1, respectively, for a deposition time of 180 s with the linear range from 1 to 5 ìg.L-1. Standard deviation for 1 to 5 ìg.L-1 arsenic concentration (n = 10) was 5%.The methodology was successfully applied for identifying and quantifying the inorganic arsenic in grape juices; and the accuracy was assessed by a recovery test on spiked samples, being 98.2% for As (III) and 96.4% for As (V). These results were compared with those from hydride generation atomic absorptions pectrometry analyses. The grape juice samples analyzed by voltammetric technique showed As (III) and As (V) concentrations ranging 51-71 ìg.L-1 and 34-60 ìg.L-1, respectively.

Adsorption of arsenic from aqueous solution on naturally available red soil.

In the present study arsenate and arsenite removal from naturally available red soil in and around Western Ghats of Maharashtra near Mumbai has been investigated. The parameters like adsorbent dose, operating pH, contact time, initial arsenite concentration, adsorbent particle size, etc. on the removal of arsenite and arsenate are examined. Kinetic study in centrifuge vessel reveals that uptake of As (III) ions is rapid in the first two hours and slows down thereafter. Maximum removal efficiency of As (III) achieved is 98% at an adsorbent dose of 45 g l-1 with initial As (III) concentration of 1000 1g l-1 in batch studies and 95% at 25 g l-1 absorbent dose under the same conditions. Equilibrium time is almost independent of initial arsenite concentration. Equilibrium studies show that As (III) ions have high affinity towards red soil even at very low concentration of arsenite. In speciation study, about 25% conversion to As (V) from As (III) is observed, with initial As (III) concentration of 1000 1gl -1 and at 25 g l-1 adsorbent dose. The results suggest that red soil could be used as effective filter medium for removal of arsenic from water.