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papers from the latest issue:
Determination of reduced glutathione, cystein and total thiols in pine pollen powder by in situ derivatization
22 October 2013,
09:28:10
Publication date: January
2014
Source:Microchemical Journal, Volume 112
Author(s): Xiao-Yong Zhang , Yu-Lian Piao , Sheng-Yun Cui , Yong-Ill Lee
Glutathione (GSH), cystein (CySH) and total thiols in pine pollen powder were determined by spectrometric, fluorometric and high performance liquid chromatographic (HPLC) assays utilizing 5,5′-dithio-bis(2-nitrobenzoic acid) (DTNB, Ellman's reagent) and o-phthaldehyde (OPA) as derivatizing agents. The pollen samples were extracted with phosphate buffer solutions (PBS) containing excess derivatizing agents concomitant with ultrasonic cell rupture. In this way, thiol groups in the samples could be effectively blocked by in situ formation of relatively stable derivatizing products just after the pollen cell ruptured, thereby effectively preventing thiol groups from oxidation during sample preparation and making it possible to perform sensitive and accurate detections. Using a precolumn derivatization method, DTNB, GSH and CySH, as well as other thiol compounds can be determined or estimated by the HPLC method. Total thiols in the samples were determined by the spectrometric method using DTNB as the derivatizing agent. GSH was also selectively determined by the fluorometric method using OPA as the derivatizing agent. The detection results indicated that abundant thiol compounds, such as GSH, CySH and thiol protein, existed in pine pollen powder with measured amounts of 0.50–0.53μmol∙g−1 of GSH, 0.41μmol∙g−1 of CySH and 4.15μmol∙g−1 of total thiols.
Source:Microchemical Journal, Volume 112
Author(s): Xiao-Yong Zhang , Yu-Lian Piao , Sheng-Yun Cui , Yong-Ill Lee
Glutathione (GSH), cystein (CySH) and total thiols in pine pollen powder were determined by spectrometric, fluorometric and high performance liquid chromatographic (HPLC) assays utilizing 5,5′-dithio-bis(2-nitrobenzoic acid) (DTNB, Ellman's reagent) and o-phthaldehyde (OPA) as derivatizing agents. The pollen samples were extracted with phosphate buffer solutions (PBS) containing excess derivatizing agents concomitant with ultrasonic cell rupture. In this way, thiol groups in the samples could be effectively blocked by in situ formation of relatively stable derivatizing products just after the pollen cell ruptured, thereby effectively preventing thiol groups from oxidation during sample preparation and making it possible to perform sensitive and accurate detections. Using a precolumn derivatization method, DTNB, GSH and CySH, as well as other thiol compounds can be determined or estimated by the HPLC method. Total thiols in the samples were determined by the spectrometric method using DTNB as the derivatizing agent. GSH was also selectively determined by the fluorometric method using OPA as the derivatizing agent. The detection results indicated that abundant thiol compounds, such as GSH, CySH and thiol protein, existed in pine pollen powder with measured amounts of 0.50–0.53μmol∙g−1 of GSH, 0.41μmol∙g−1 of CySH and 4.15μmol∙g−1 of total thiols.
Flow injection hydride generation for on-atomizer trapping: Highly sensitive determination of cadmium by tungsten coil atomic absorption spectrometry
22 October 2013,
09:28:10
Publication date: January
2014
Source:Microchemical Journal, Volume 112
Author(s): Piaopiao Chen , Yujia Deng , Kuncheng Guo , Xiaoming Jiang , Chengbin Zheng , Xiandeng Hou
Here we report the use of the tungsten-coil atomizer of a portable atomic absorption spectrometer as an on-atomizer trapping device and atomizer for the determination of trace cadmium, with flow injection hydride generation for production of volatile cadmium species from sample solutions. By mixing acidic analyte solution with tetrahydroborate solution, volatile cadmium species is produced and separated from the solution, and then transported and impacted onto the surface of the atomizer with a heating current set at 2.3A. Subsequent atomic absorption measurement was accomplished with in situ atomization at 8.5A. Compared to conventional direct injection, the sensitivity and the limit of detection were improved by 58- and 66-fold, respectively, based on 5.0mL sampling volume. In addition, use of flow injection significantly improved sample throughput. The proposed method was used for the analysis of several real water samples with good spiked recoveries.
Source:Microchemical Journal, Volume 112
Author(s): Piaopiao Chen , Yujia Deng , Kuncheng Guo , Xiaoming Jiang , Chengbin Zheng , Xiandeng Hou
Here we report the use of the tungsten-coil atomizer of a portable atomic absorption spectrometer as an on-atomizer trapping device and atomizer for the determination of trace cadmium, with flow injection hydride generation for production of volatile cadmium species from sample solutions. By mixing acidic analyte solution with tetrahydroborate solution, volatile cadmium species is produced and separated from the solution, and then transported and impacted onto the surface of the atomizer with a heating current set at 2.3A. Subsequent atomic absorption measurement was accomplished with in situ atomization at 8.5A. Compared to conventional direct injection, the sensitivity and the limit of detection were improved by 58- and 66-fold, respectively, based on 5.0mL sampling volume. In addition, use of flow injection significantly improved sample throughput. The proposed method was used for the analysis of several real water samples with good spiked recoveries.
Emerging issues on degradation by-products deriving from personal care products and pharmaceuticals during disinfection processes of water used in swimming pools
22 October 2013,
09:28:10
Publication date: January
2014
Source:Microchemical Journal, Volume 112
Author(s): Paola Bottoni , Lucia Bonadonna , Mattea Chirico , Sergio Caroli , Gyula Záray
The use of disinfection substances in the sanitation and disinfection processes of artificial water used for sports amenities and swimming pools has recently raised some serious concerns. Recreational Water Illnesses (RWIs) can put at serious risk the health of bathers and swimmers due to adverse effects caused by the use of disinfection chemicals, such as chlorine, chloramine, ozone and UV radiation, as well as their by-products. Remarkable documented evidence is available on the impact of Disinfection By-Products (DBPs), such as chloroform and other trihalomethanes, haloacetic acids and chlorophenols, deriving from the oxidation of common organic pollutants dissolved in raw, drinking, waste and artificial waters. Appropriate countermeasures, aimed at avoiding bathers' exposures to these chemicals, have been developed and adopted in public and private structures, also through important scientific contributions and technical provisions issued by the WHO and some national health authorities. On the other hand, it has been demonstrated that high reactive disinfection agents may transform other undesirable chemicals released by bathers, namely pharmaceuticals, sunscreens and other Pharmaceuticals and Personal Care Products (PPCPs) into chlorinated and oxidized compounds and nitrosamine precursors. The first symptoms of potentially adverse health effects on human subjects of these largely unknown by-products should be adequately taken into consideration and investigated.
Source:Microchemical Journal, Volume 112
Author(s): Paola Bottoni , Lucia Bonadonna , Mattea Chirico , Sergio Caroli , Gyula Záray
The use of disinfection substances in the sanitation and disinfection processes of artificial water used for sports amenities and swimming pools has recently raised some serious concerns. Recreational Water Illnesses (RWIs) can put at serious risk the health of bathers and swimmers due to adverse effects caused by the use of disinfection chemicals, such as chlorine, chloramine, ozone and UV radiation, as well as their by-products. Remarkable documented evidence is available on the impact of Disinfection By-Products (DBPs), such as chloroform and other trihalomethanes, haloacetic acids and chlorophenols, deriving from the oxidation of common organic pollutants dissolved in raw, drinking, waste and artificial waters. Appropriate countermeasures, aimed at avoiding bathers' exposures to these chemicals, have been developed and adopted in public and private structures, also through important scientific contributions and technical provisions issued by the WHO and some national health authorities. On the other hand, it has been demonstrated that high reactive disinfection agents may transform other undesirable chemicals released by bathers, namely pharmaceuticals, sunscreens and other Pharmaceuticals and Personal Care Products (PPCPs) into chlorinated and oxidized compounds and nitrosamine precursors. The first symptoms of potentially adverse health effects on human subjects of these largely unknown by-products should be adequately taken into consideration and investigated.
Single-step procedure for trace element determination in synovial fluid by dynamic reaction cell-inductively coupled plasma mass spectrometry
22 October 2013,
09:28:10
Publication date: January
2014
Source:Microchemical Journal, Volume 112
Author(s): Franco Moyano , Ernesto Verni , Héctor Tamashiro , Silvia Digenaro , Luis D. Martinez , Raúl A. Gil
A fast and single-step procedure for the dissolution of human synovial fluid in formic acid and further determination by dynamic reaction cell-inductively coupled plasma mass spectrometry (DRC-ICPMS) with a high-efficiency sample introduction system was developed. The samples were collected, treated and analyzed in the same screw-capped tubes. In order to overcome the effect of considerable carbon content, the sample introduction, nebulization and ICP operating conditions were carefully optimized. Furthermore, DRC technology with CH4 as reaction gas was used for the elimination of spectral interferences due to polyatomic ions. The effect of the sample matrix was evaluated and mitigated through comparison of direct calibration against aqueous standards, direct calibration in formic acid media and analyte addition calibration. The recommended procedure involved low dilution and low detection limits (from 0.003μgL−1 for U to 13.3μgL−1 for Ti) with adequate precision (from 0.6% for Co to 6.6% for Ti). The proposed method was successfully applied to determine 16 trace elements in concentrations from 0.03μgL−1 (Cd) to 88.2μgL−1 (Cu) in human synovial fluid samples.
Source:Microchemical Journal, Volume 112
Author(s): Franco Moyano , Ernesto Verni , Héctor Tamashiro , Silvia Digenaro , Luis D. Martinez , Raúl A. Gil
A fast and single-step procedure for the dissolution of human synovial fluid in formic acid and further determination by dynamic reaction cell-inductively coupled plasma mass spectrometry (DRC-ICPMS) with a high-efficiency sample introduction system was developed. The samples were collected, treated and analyzed in the same screw-capped tubes. In order to overcome the effect of considerable carbon content, the sample introduction, nebulization and ICP operating conditions were carefully optimized. Furthermore, DRC technology with CH4 as reaction gas was used for the elimination of spectral interferences due to polyatomic ions. The effect of the sample matrix was evaluated and mitigated through comparison of direct calibration against aqueous standards, direct calibration in formic acid media and analyte addition calibration. The recommended procedure involved low dilution and low detection limits (from 0.003μgL−1 for U to 13.3μgL−1 for Ti) with adequate precision (from 0.6% for Co to 6.6% for Ti). The proposed method was successfully applied to determine 16 trace elements in concentrations from 0.03μgL−1 (Cd) to 88.2μgL−1 (Cu) in human synovial fluid samples.
Modeling of second-order spectrophotometric data generated by a pH-gradient flow injection technique for the determination of doxorubicin in human plasma
22 October 2013,
09:28:10
Publication date: January
2014
Source:Microchemical Journal, Volume 112
Author(s): Mirta R. Alcaráz , Agustina V. Schenone , María J. Culzoni , Héctor C. Goicoechea
In this paper, the development of a pH-gradient flow-injection method with diode-array spectrophotometric detection combined with extended multivariate curve resolution–alternating least-squares (MCR–ALS) to quantitate doxorubicin in the presence of rifampicin in plasma samples is presented. Quantitation of doxorubicin was based on acid–base and spectral differences between its species and those for the interference. Overlapped profiles among the analyte and the interference were mathematically solved by data modeling with the well-known extended MCR–ALS algorithm. The method, which involves a simple sample pretreatment consisting in the addition of trichloroacetic acid followed by centrifugation, was applied to resolve validation mixtures composed of human plasma spiked with doxorubicin. Acceptable analytical figures of merit were obtained, i.e. recoveries from 96 to 107%, coefficients of variation between 0.2% and 7.8%, and limits of detection and quantification of 0.77 and 2.32μgL−1, respectively.
Source:Microchemical Journal, Volume 112
Author(s): Mirta R. Alcaráz , Agustina V. Schenone , María J. Culzoni , Héctor C. Goicoechea
In this paper, the development of a pH-gradient flow-injection method with diode-array spectrophotometric detection combined with extended multivariate curve resolution–alternating least-squares (MCR–ALS) to quantitate doxorubicin in the presence of rifampicin in plasma samples is presented. Quantitation of doxorubicin was based on acid–base and spectral differences between its species and those for the interference. Overlapped profiles among the analyte and the interference were mathematically solved by data modeling with the well-known extended MCR–ALS algorithm. The method, which involves a simple sample pretreatment consisting in the addition of trichloroacetic acid followed by centrifugation, was applied to resolve validation mixtures composed of human plasma spiked with doxorubicin. Acceptable analytical figures of merit were obtained, i.e. recoveries from 96 to 107%, coefficients of variation between 0.2% and 7.8%, and limits of detection and quantification of 0.77 and 2.32μgL−1, respectively.
Graphical abstract
Effects of UV-dechloramination of swimming pool water on the formation of disinfection by-products: A lab-scale study
22 October 2013,
09:28:10
Publication date: January
2014
Source:Microchemical Journal, Volume 112
Author(s): Nicolas Cimetiere , Joseph De Laat
UV dechloramination has become a very popular process for reducing the concentration of chloramines in public swimming pool water. As the effects of this process on the formation of disinfection by-products (DBPs) remain a controversial issue, a bench-scale study has been undertaken to examine the impact of UV dechloramination on the formation of various DBPs. Four pool water samples were exposed to UV radiation at 254nm in the presence of free chlorine ([Cl2]0 =3mgL−1) and then chlorinated in the dark for 24h ([Cl2]0 =3mgL−1). High UV doses (up to 47kJm−2) were used to simulate cumulative UV doses received by real pool waters. The data showed that UV irradiation led to a 90% photodecay of free chlorine for UV doses ranging from 13 to 20kJm−2, to the formation of chlorate ion (0.05–0.11mol of chlorate/mole of free chlorine decomposed) and to a significant increase in the chlorine demand of pool water during the post-chlorination step. UV exposure followed by post-chlorination did not significantly affect the formation of haloacetic acids, led to a small increase in the concentrations of adsorbable organic halogen (AOX) and of chloral hydrate and markedly increased the formation of trihalomethanes (chloroform, bromodichloromethane, chlorodibromomethane), dichloroacetonitrile, 1,1,1-trichloropropanone and chloropicrin.
Source:Microchemical Journal, Volume 112
Author(s): Nicolas Cimetiere , Joseph De Laat
UV dechloramination has become a very popular process for reducing the concentration of chloramines in public swimming pool water. As the effects of this process on the formation of disinfection by-products (DBPs) remain a controversial issue, a bench-scale study has been undertaken to examine the impact of UV dechloramination on the formation of various DBPs. Four pool water samples were exposed to UV radiation at 254nm in the presence of free chlorine ([Cl2]0 =3mgL−1) and then chlorinated in the dark for 24h ([Cl2]0 =3mgL−1). High UV doses (up to 47kJm−2) were used to simulate cumulative UV doses received by real pool waters. The data showed that UV irradiation led to a 90% photodecay of free chlorine for UV doses ranging from 13 to 20kJm−2, to the formation of chlorate ion (0.05–0.11mol of chlorate/mole of free chlorine decomposed) and to a significant increase in the chlorine demand of pool water during the post-chlorination step. UV exposure followed by post-chlorination did not significantly affect the formation of haloacetic acids, led to a small increase in the concentrations of adsorbable organic halogen (AOX) and of chloral hydrate and markedly increased the formation of trihalomethanes (chloroform, bromodichloromethane, chlorodibromomethane), dichloroacetonitrile, 1,1,1-trichloropropanone and chloropicrin.
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