Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants whose carcinogenicity and mutagenicity have been extensively studied. 1They are byproducts of the incomplete combustion of fuels and wood, and persist in the environment. 2 The concentrations of PAHs in the atmosphere are regarded as indicators of air pollution, and the historical trends of PAHs recorded in the sediment core from a reservoir should reflect the changes in the atmospheric pollution around the reservoir. 3 In order to evaluate the atmospheric environment at the sampling point and the historical trend of the PAH risk in the atmospheric environment, it is very important to establish an analytical method for PAHs in sediment samples.Tsuji et al. reported a method for the determination of PAHs in sediment using ultrasonic extraction of the PAHs and a cleanup solid-phase extraction procedure, followed by LC/fluorescence detector. 4 However, it is difficult to detect PAHs which have a poor fluorescence, such as indeno [1,2,3-c,d]pyrene, using the fluorescence detector.The LC/MS method would supply more useful information for the analysis of PAHs because of the relatively high specificity of the MS detector compared to the UV or fluorescence detector. However, very few examples are known based on the detection of PAHs by LC/MS using several commercially available interfaces, including thermospray, 5 liquid ionization 6 and atmospheric pressure chemical ionization.7 Furthermore, there were only a few reports about the detection of PAHs using electrospray as the interface due to difficulty of ionizing low polar compounds. 8,9 Recently, Bruins et al. introduced the dopant assisted atmospheric pressure photoionization (APPI) technique, which was a novel LC/MS ionization and can achieve the ionization of low polar compounds, such as PAHs. 10,11 However, there are few reports on the application of this technique to environmental analysis. 12 In this report, we present a method for the determination of PAHs in sediment samples by the ultrasonic extraction of PAHs and a clean-up solid-phase extraction procedure followed by LC/APPI/MS. Experimental MaterialsThe following 12 PAHs were detected and determined in this study: phenanthrene (Phe), anthracene (An), fluoranthene (Flu), pyrene (Py), benzo(a)anthracene (B(a)A), chrysene (Chr), benzo(b)fluoranthene (B(b)F), benzo(k)fluoranthene (B(k)F), benzo(a)pyrene (B(a)P), benzo(e)pyrene (B(e)P), benzo(ghi)perylene (BghiP) and indeno [1,2,3-c,d]pyrene (IP). These compounds were obtained from SUPELCO (Tokyo, Japan). All solvents were of HPLC grade, while the other chemicals were of analytical-reagent grade. Benzo(a)pyrene-d12 was used as the internal standard, and purchased from Hayashi Pure Chemical Industries (Osaka, Japan). Ammonium acetate and acetic acid were obtained from Wako Pure Chemical (Osaka, Japan). Ultra-pure water was produced by a Milli-Q system (Millipore, Bedford, USA). A sediment sample was obtained from Nagaike, which is a reservoir located in the southern part of Osaka C...

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A sheath-flow capillary electrophoresis-mass spectrometry (CE-MS) system utilizing a fully integrated large-bore stainless-steel emitter electrode tapered at the end for micro-ionspray operation has been developed and evaluated. A separation capillary with an outer diameter of up to 360 microm was inserted into the electrode thus forming a void volume of less than 15 nL between the capillary end and the electrospray ionisation (ESI) tip. The sheath liquid, usually methanol-water (80:20) with 0.1% formic acid for positive ion mode or methanol for negative ion mode, was delivered at 0.5-1.0 microL/min. Unlike previously reported CE-MS interfaces, the CE-MS probe was incorporated directly onto an Applied Biosystems/MDS SCIEX orthogonal-spray Turbo "V" ion source for ease of use and automatic operation. This integration enables fast and facile coupling and replacement of the separation capillary without interrupting the ion source configuration, and the sheath liquid supply. The reusable electrospray electrode was precisely fabricated and aligned with the length of the nebulizing gas tube for improved reproducibility. Automation was achieved through software control of both CE and tandem MS (MS/MS) for unattended batch sample analysis. The system was evaluated for attomole- to low femtomole-level profiling of model peptides and protein mixtures, bisphosphates, as well as antiviral nucleosidic drugs in cellular extracts.

In anaerobic waste fermentation processes, the gas composition and production rate are key indicators of reactor performance. Several systems have been devised to measure the gas production rate (flow rate) in the range usually found in laboratory-scale anaerobic digesters (1 -100 mL/min), most of them using liquid displacement measurements. Recent typical gas measurement devices have been described by Van den Berg,' Moletta and Albagnac,2 Glauser and coworkers,3 and Erdman and D e l~i c h e .~ However, liquid displacement techniques are often inconvenient for various reasons, namely gas solubility in the displaced liquid, liquid evaporation, difficulty of operation and automation in industrial environments. The development of a simple fast response gas metering system which avoids these problems thus seemed a highly desirable goal. The work described here was therefore undertaken: 1) to design a low-cost, electronic gas flow measurement system which could simultaneously monitor the gas production PRESSURE TRANSDUCER n rates of several digesters and 2) to develop a microcomputer interface for data acquisition and processing. THE FLOW SYSTEMThe flow metering system, as illustrated schematically in Figure 1, consists of a three-way solenoid valve connected to a pressure transducer, a glass bulb (ballast), and the vapor space of the monitored reactor. The three-way (stainless steel) solenoid valve is set so that the two normally-open ports (1 and 2) communicate with the transducer and ballast. The third port is normally closed; in the open position, it vents the ballast and transducer to the atmosphere.The operation of the flow system is quite straightforward. With the third port normally closed, the pressure in the reactor and ballast increases progressively. As the transducer VENT VALVE Figure 1. Schematic description of the flow systems used to measure gas flow rates. BIOPROCESS

Halogen-assisted electrothermal vaporization (ETV) was used as a sample introduction mechanism for inductively coupled plasma atomic emission spectrometry. Freon-12™ was used as a gas-phase halogenation reagent in the ETV graphite furnace to enhance vaporization of carbide-forming elements by converting them into metal halides. With Freon ETV, detection levels for Zn, Pb, Cd, Mn, V, Cu, Ti, and Ca were lower than those obtained with conventional nebulization of liquid standards. A zeolite sample was analyzed for the refractory elements chromium and vanadium. Without Freon, the signals for these elements were very low; however, with Freon, the signals were dramatically improved. Detection limits of 1.4 μg/g and 0.3 μg/g, respectively, were obtained for these elements. A sheathing and cooling gas flow was introduced to reduce analyte vapor condensation on tubing walls and to promote aggregate formation. This additional flow enhanced the quality of signal with the zeolite but proved to be detrimental for the determination of refractory elements in liquid standards with or without halogenation. The precision of determination for the zeolite sample varied from 3% for cadmium, to 6% for lead.