JP2015161636A - Mercury atomic fluorescence analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mercury atomic fluorescence spectrometer capable of performing highly accurate analysis without reduction in sensitivity no matter when measurement is started.SOLUTION: A mercury atomic fluorescence spectrometer 70 comprises: a mercury collecting tube 1 filled with a mercury collection agent 11 for collecting mercury in a sample gas; heating vaporization means 2 for heating the mercury collecting tube 1 so as to vaporize mercury; a mercury measuring instrument 4 for measuring the amount of the mercury heated and vaporized by the heating vaporization means 2; valves V1 and V2 installed in a carrier gas passage through which a carrier gas G flows; and control means 3 for controlling the heating vaporization means 2 and the valves V1 and V2. At a timing of purge set by the control means 3, the control means 3 controls the heating vaporization means 2 and the valves V1 and V2 to heat the mercury collecting tube 1 to 300-800°C and to flow the carrier gas G into the mercury collecting tube 1 so as to purge the mercury collecting tube 1.

Description

  The present invention relates to a mercury atomic fluorescence analyzer for analyzing mercury contained in a sample.

  When air is used as a carrier gas during measurement with a mercury atomic fluorescence analyzer, the atomic fluorescence intensity of mercury becomes extremely low due to the quenching phenomenon of air (oxygen), so argon gas is generally used as the carrier gas (patent) Reference 1).

  Therefore, before the measurement is started after the mercury atom fluorescence analyzer is turned on, the measurement is performed after flowing argon gas into the carrier gas channel of the mercury atom fluorescence analyzer and replacing the air with argon gas.

JP 2010-151499 A

  However, even if measurement is started after argon gas is flowed into the carrier gas channel of the mercury atomic fluorescence analyzer and air is replaced with argon gas before the measurement is started after the mercury atomic fluorescence analyzer is turned on. In some cases, the sensitivity is lowered, and when the waiting time from the end of the measurement to the start of the next measurement is increased, the sensitivity is lowered.

  The present invention has been made in view of the above-described conventional problems, and an object thereof is to provide a mercury atomic fluorescence analyzer capable of performing a highly accurate analysis without any reduction in sensitivity no matter what time the measurement starts.

  In order to achieve the above object, a mercury atomic fluorescence analyzer according to the first configuration of the present invention includes a mercury collecting tube filled with a mercury collecting agent for collecting mercury in a sample gas, and the mercury collecting A heating vaporization means for vaporizing mercury by heating a tube; a mercury measuring device for quantifying mercury heated and vaporized by the heating vaporization means; a valve provided in a carrier gas channel through which a carrier gas flows; and the heating vaporization And a control means for controlling the valve, and at the time of purge setting set in the control means, the control means controls the heating vaporization means and the valve to control the mercury collecting pipe to 300. While heating at a temperature of from -800 ° C., a carrier gas is passed through the mercury collection tube to purge the mercury collection tube.

  According to the mercury atomic fluorescence spectrometer according to the first configuration of the present invention, the mercury collecting tube is heated to 300 ° C. to 800 ° C. at an appropriate timing, and a carrier gas is allowed to flow through the mercury collecting tube for purging. Therefore, no matter what time the measurement starts, there is no decrease in sensitivity, and highly accurate analysis can be performed.

  In the mercury atomic fluorescence spectrometer according to the first configuration of the present invention, it is preferable that the start of measurement after the power is turned on before the purge setting. With this configuration, even when measurement is performed immediately after the mercury atomic fluorescence analyzer is turned on, the sensitivity is not lowered, and high-precision analysis can be performed.

  In the mercury atomic fluorescence spectrometer according to the first configuration of the present invention, the control means monitors the time from the end of the measurement to the start of the next measurement as a standby time, and the purge unnecessary time set in the control means It is preferable to set the purge setting before the start of measurement after elapse of. With this configuration, even when the measurement is performed after a long waiting time, the sensitivity is not lowered and a highly accurate analysis can be performed.

  The mercury atomic fluorescence spectrometer according to the second configuration of the present invention includes a mercury collecting tube filled with a mercury collecting agent for collecting mercury in a sample gas, and vaporizing mercury by heating the mercury collecting tube. Heating vaporization means, a mercury measuring device for quantifying mercury heated and vaporized by the heating vaporization means, a valve provided in a carrier gas channel through which a carrier gas flows, and a control for controlling the heating vaporization means and the valve And when the purge measurement is set in the control means, the control means controls the heating vaporization means and the valve to heat the mercury collecting tube to the same temperature as the sample measurement. Then, the purge measurement is performed at least once by flowing the carrier gas at the same flow rate as the sample measurement into the mercury collecting tube.

  According to the mercury atomic fluorescence spectrometer according to the second configuration of the present invention, the mercury collecting tube is heated to the same temperature as when measuring the sample at an appropriate timing, and the mercury collecting tube has the same flow rate as when measuring the sample. Since the purge measurement for flowing the carrier gas is performed at least once, the sensitivity does not decrease at any time when the measurement is started, and a highly accurate analysis can be performed.

  In the mercury atomic fluorescence spectrometer according to the second configuration of the present invention, it is preferable that the start of measurement after the power is turned on is set as the purge measurement. With this configuration, even when measurement is performed immediately after the mercury atomic fluorescence analyzer is turned on, the sensitivity is not lowered, and high-precision analysis can be performed.

  In the mercury atomic fluorescence spectrometer according to the second configuration of the present invention, the control means monitors the time from the end of the measurement to the start of the next measurement as a standby time, and the standby time set in the control means is not required. It is preferable to set the purge measurement before the start of measurement after a lapse of time. With this configuration, even when the measurement is performed after a long waiting time, the sensitivity is not lowered and a highly accurate analysis can be performed.

It is a schematic block diagram of the mercury atomic fluorescence analyzer of the first and second embodiments of the present invention. It is the schematic of the mercury measuring device of the same apparatus. It is a flowchart of operation | movement of the mercury atom fluorescence analyzer of 1st Embodiment of this invention. It is a flowchart of operation | movement of the mercury atom fluorescence analyzer of 2nd Embodiment of this invention. It is the measurement data measured with the same device. It is an enlarged view of the measurement data. It is a figure which shows the relationship between standby time and a sensitivity fall. It is a figure which shows the relationship between the air content rate in argon gas, and a sensitivity fall. Experiment A data. Experiment B data. Experimental C data.

  Hereinafter, a mercury atom fluorescence analyzer according to a first embodiment of the present invention will be described. FIG. 1 schematically shows a mercury atomic fluorescence analyzer 70 according to the first embodiment of the present invention. This mercury atomic fluorescence analyzer 70 is a device for measuring atmospheric mercury, and includes a mercury collecting tube 1 filled with a mercury collecting agent 11 for collecting mercury in a sample gas, and a mercury collecting tube 1. Heated vaporization means 2 that is heated and vaporized, for example, a heating vaporization furnace, a mercury measuring device 4 that quantifies mercury vaporized by heating and vaporization means 2, and a carrier gas flow path through which a carrier gas G flows And control means 3 for controlling the heating and vaporizing means 2 and the valves V1 and V2. When the purge setting is set in the control means 3, the control means 3 is connected to the heating and vaporizing means 2 and the valves. The mercury collecting tube 1 is heated to 300 ° C. to 800 ° C. by controlling V1 and V2, and the mercury collecting tube 1 and the carrier gas channel are purged by flowing the carrier gas G through the mercury collecting tube 1 To do.

  At the time of the purge setting set in the control means 3, the same carrier gas G that is flowed at the time of sample measurement, for example, argon gas G1 is flowed, and the mercury in the sample gas S is collected in the mercury collecting tube 1 Sometimes air G2 is flowed as the carrier gas G. The mercury atom fluorescence analyzer 70 includes a pump P that sucks the carrier gas G into the carrier gas channel into the mercury atom fluorescence analyzer 70, a valve V3 that adjusts the flow rate of the carrier gas G sucked by the pump P, and an argon gas. A mass flow controller 5 for adjusting the flow rate of G1. The valve V1 is an open / close electromagnetic valve, the valve V2 is a three-way electromagnetic valve, and the valve V3 is a manual flow control valve. The control means 3 is provided in the computer 6, for example, and the control means 3 controls the entire apparatus including the mercury measuring device 4, the mass flow controller 5, and the pump P. The carrier gas G that is flowed at the time of sample measurement is not limited to the argon gas G1, but may be nitrogen gas, neon gas, helium gas, or the like.

  In this specification, the measurement means that the mercury in the sample gas is collected in the mercury collecting agent 11, and the collected mercury is vaporized by heating to become gaseous mercury, which is quantified by the mercury measuring device 4. Process to be performed. Sample measurement refers only to a process in which mercury in the sample gas S is not collected by the mercury scavenger 11 and gaseous mercury is quantified by the mercury measuring device 4.

  In the mercury collecting tube 1, 20-30 mesh granular diatomaceous earth is placed in an acidic aqueous solution in which gold nanoparticles are dispersed at a high concentration (for example, 50 to 90 wt%), and gold nanoparticle is added to the diatomaceous earth (chromosolve). The mercury collecting agent 11 impregnated with particles and heat-treated is filled. The mercury scavenger 11 may be one obtained by baking chloroauric acid on diatomaceous earth. Diatomaceous earth is a carrier supporting gold nanoparticles, and sea sand may be used for this carrier.

  The mercury collecting tube 1 is filled with quartz wool at the inlet and outlet of a cylindrical container made of quartz, for example, and a mercury collecting agent 11 is filled between these quartz wools. The mercury collecting tube 1 is inserted into the heating vaporization means 2 and heated.

  The purge setting time set in the control means 3 is, for example, the time before the start of measurement after the mercury atom fluorescence analyzer 70 is turned on, and the time from when the control means ends the measurement until the start of the next measurement. The waiting time is before the start of measurement after the purge unnecessary time set in the control means has elapsed.

  As shown in FIG. 2, the mercury measuring device 4 is radiated from a sample measuring cell 42 for measuring the sample gas S, a mercury lamp 41 for irradiating the sample measuring cell 42 with a mercury analysis line, and the mercury lamp 41. A position where the analysis line is not incident, and a position where mercury present in the sample gas S introduced into the sample measurement cell 42 is excited by the analysis line irradiated from the mercury lamp 41 and the fluorescence intensity of mercury generated can be detected. And a detection processing unit 44 that quantifies the mercury content in the sample gas S in accordance with the fluorescence intensity of mercury detected by the detector 43.

  As shown in FIG. 1, the carrier gas flow path includes a sample inlet C1 for introducing the sample gas S or air G2 into the mercury atomic fluorescence analyzer 70, and an open / close electromagnetic valve that is opened when the sample gas S or air G2 is introduced. V1, an argon gas inlet C2 for introducing argon gas G1 into the mercury atomic fluorescence analyzer 70, a mass flow controller 5 for adjusting the argon gas flow rate, a connection channel C3 for connecting the sample gas channel and the argon gas channel, mercury The collection tube 1, the carrier gas G passing through the mercury collection tube 1 is branched into a flow path between the mercury measuring device 4 and the three-way electromagnetic valve V <b> 2, and the measurement cell 42 ( 2), three-way electromagnetic valve V2, flow rate adjusting valve V3, pump P for sucking carrier gas G, and outlet C5 for discharging carrier gas G from mercury atom fluorescence analyzer 70. Et al constructed. The open / close electromagnetic valve V1 is closed when the power is shut off, and is opened when energized. The three-way solenoid valve V2 has the mercury collecting tube side flow path open and the mercury measuring device side flow path closed when the power is cut off, and the mercury collecting tube side flow path is closed when energized. As a result, the mercury meter side flow path is opened.

  Next, the operation of the mercury atomic fluorescence analyzer 70 according to the first embodiment of the present invention will be described. FIG. 3 is a schematic flow diagram of the operation of the mercury atomic fluorescence analyzer 70, focusing on the operation of purging the mercury collection tube 1 with the argon gas G1. When the mercury atomic fluorescence analyzer 70 is turned on, the mercury measuring device 4 is warmed up (mainly stabilizing the mercury lamp 41), and the control means 3 controls the heating vaporization means 2 to control the mercury collecting tube. 1 is heated to, for example, 150 ° C. to enter a standby state. The control means 3 is set so as to purge the mercury collecting tube 1 by setting the purge start (when the first purge is set) before the start of measurement after the mercury atomic fluorescence analyzer 70 is turned on. The heating temperature of the mercury collecting tube 1 in the standby state is the same as the heating temperature when the mercury in the sample gas S is collected by the mercury collecting agent 11 of the mercury collecting tube 1. The reason for heating the mercury collecting tube 1 to 150 ° C. in the standby state is to prevent the surface of the mercury collecting agent 11 from being contaminated by hydrocarbons in the air, interference components, and the like. The collection of mercury in the sample gas S will be described later.

  When the mercury atomic fluorescence analyzer 70 is in a standby state, the first purge is started. In the first purge, the control means 3 controls the heating vaporization means 2 to heat the mercury collecting tube 1 to, for example, 500 ° C., and the argon gas G1 sucked by the pump P from the argon gas inlet C2 is mass-flowed. It flows in the order of the controller 5, the branch path C3, the mercury collecting pipe 1 heated to 500 ° C., the branch path C4, the three-way electromagnetic valve V2, the flow rate adjusting valve V3, the pump P and the discharge port C5 (FIG. 1). A flow path through which the argon gas G1 flows in this order is referred to as a first purge carrier gas flow path.

  As the argon gas G1 flows through the first purge carrier gas flow path, the first purge carrier gas flow path is purged. At this time, the open / close electromagnetic valve V1 is in a closed state where the power supply is shut off, and the three-way electromagnetic valve V2 is in an open state where the mercury collecting tube side flow path is in the power cut off state and the mercury measuring instrument side flow path is closed. Is adjusted to 0.4 L (liter) / min by the mass flow controller 5. The purge time for the first purge is, for example, 30 seconds. The first purge time is not limited to 30 seconds, and may be shorter or longer than 30 seconds. For high accuracy analysis, a long purge time is preferred.

  When the first purge is finished, the second purge is started. In the second purge, the argon gas G1 sucked by the pump P from the argon gas inlet C2 is supplied to the mass flow controller 5, the connection channel C3, the mercury collecting tube 1 heated to 500 ° C., the branch channel C4, and the mercury measuring device 4. The sample measurement cell 42 (FIG. 2), the three-way electromagnetic valve V2, the flow rate adjustment valve V3, the pump P, and the discharge port C5 flow in this order (FIG. 1). A channel through which the argon gas G1 flows in this order is referred to as a second purge carrier gas channel. As the argon gas G1 flows through the second purge carrier gas channel, the second purge carrier gas channel is purged.

  At this time, the open / close electromagnetic valve V1 is in a closed state in which the power is shut off, the three-way electromagnetic valve V2 is energized, the mercury collecting pipe side flow path is closed, and the mercury measuring instrument side flow path is open. The argon gas G1 is adjusted to 0.4 L / min by the mass flow controller 5. The purge time for the second purge is, for example, 180 seconds. In the second purge, since the sample measurement cell 42 is purged, the purge is performed for a longer time than the first purge. The second purge time is not limited to 180 seconds, and may be shorter or longer than 180 seconds. For high accuracy analysis, a long purge time is preferred.

  By the first purge and the second purge, the first purge carrier gas channel and the second purge carrier gas channel are purged, and all the carrier gas channels of the mercury atomic fluorescence analyzer 70 are purged. By the first and second purges, air and moisture (humidity) that have entered the carrier gas flow path while the mercury atomic fluorescence analyzer 70 is powered off are purged. In particular, in the first purge and the second purge, the mercury collection tube 1 is purged with the argon gas G1 which is the carrier gas G at the time of sample measurement while being heated to 500 ° C. Therefore, the mercury atomic fluorescence analyzer 70 is turned off. In the meantime, in the mercury collecting agent 11 filled in the mercury collecting tube 1, the air and moisture that enter the gaps between the gold nanoparticles, the porous pores of the diatomaceous earth, the gaps between the particles of the diatomaceous earth, and the like are efficiently expelled. It is.

  When the second purge is finished, the control means 3 monitors the time from the end of the second purge to the start of measurement as a standby time. The control means 3 is set so as to purge the mercury collecting tube 1 when the waiting time has elapsed after the purge unnecessary time set in the control means 3 has elapsed and before the start of measurement is set at the time of purge setting (when the second purge is set). Yes. Before the start of measurement, the control means 3 determines whether or not the standby time exceeds a purge unnecessary time, for example, 1 hour. If the standby time exceeds 1 hour, the first purge and the second purge are performed again. Purge is performed.

  If the waiting time is within 1 hour, the measurement is started and mercury in the sample gas S is collected in the mercury collecting agent 11. In order to collect mercury in the sample gas S in the mercury collecting agent 11, the control means 3 controls the heating and vaporizing means 2 so that the heating temperature of the mercury collecting pipe 1 is set to 150 ° C., for example, and the mass flow controller 5 is In the closed state (the state where the argon gas G1 does not flow), the open / close electromagnetic valve V1 is opened and the pump P is driven to introduce the sample gas S from the sample introduction port C1, and mercury in the sample gas S is collected. Collect in Agent 11. At this time, the sample gas S passes through the open / close electromagnetic valve V1, the branch path C3, the mercury collecting pipe 1, the branch path C4, the three-way electromagnetic valve V2, the flow rate adjustment valve V3, the pump P, and the discharge port C5 heated to 150 ° C. It flows in order. The flow rate of the sample gas S is adjusted to 0.5 L / min by the flow rate adjusting valve V3, and is introduced, for example, for 5 minutes. The flow rate and introduction time for introducing the sample gas S are appropriately adjusted according to the type of the sample gas S.

  When the mercury in the sample gas S is collected by the mercury collecting agent 11, the air flowing into the carrier gas channel at the time of collecting the mercury is replaced with the argon gas G1. Before the sample measurement, the control means 3 controls the heating vaporization means 2, the mass flow controller 5, the open / close electromagnetic valve V1, the three-way electromagnetic valve V2, and the pump P, and the heating temperature of the mercury collecting tube 1 is the same as when collecting mercury. The temperature is maintained at 150 ° C., and argon gas G1 is allowed to flow through the carrier gas flow path to replace the air with argon gas. After this argon gas replacement is performed, sample measurement is started. When the sample measurement is started, the mercury collecting tube 1 is heated to 500 ° C. by the heating and vaporizing means 2, and the mercury collected in the mercury collecting agent 11 is heated and vaporized to become gaseous mercury. Gaseous mercury is carried to the mercury measuring device 4 by the argon gas G1 introduced from the argon gas inlet C2, and the sample is measured. Argon gas G1 during sample measurement flows through the second purge carrier gas flow path. The argon gas G1 is adjusted to 0.1 L / min by the mass flow controller 5.

  When the measurement is completed, the control means 3 monitors the time from the end of the measurement to the start of the next measurement as a standby time. The control means 3 is set so as to purge the mercury collecting tube 1 by setting the time before the start of measurement after the purge unnecessary time set in the control means 3 has elapsed to the time of purge setting (when the third purge is set). Yes. Before the start of the next measurement, the control means 3 determines whether or not the standby time exceeds the purge unnecessary time, for example, 1 hour, and if it is within 1 hour, the next measurement is started.

  If the standby time exceeds 1 hour, the next measurement is started after the first purge and the second purge are performed.

  In the mercury atomic fluorescence spectrometer 70 according to the first embodiment of the present invention, the first to third purge setting times are set in the control means 3 as the purge setting time. Either one at the time of 3 purge setting or any two may be sufficient. Four or more purges may be set.

  In the mercury atomic fluorescence spectrometer 70 of the first embodiment of the present invention, the heating temperature of the standby mercury collecting tube 1 and the heating temperature of the mercury collecting tube 1 when collecting mercury in the sample gas S are 150 ° C. However, it is not limited to this heating temperature, and if the heating temperature exceeds 200 ° C., the mercury collecting efficiency of the mercury collecting tube 1 decreases, so that the heating temperature is in the range of 150 ° C. to 200 ° C. Good. Moreover, although the heating temperature of the mercury collecting tube 1 at the time of the second purge and the sample measurement is 500 ° C., it is not limited to this heating temperature, and if the heating temperature is less than 300 ° C., the mercury collecting agent Since the vaporization efficiency of the mercury collected by 11 falls, it should just be the heating temperature of the range of 300 to 800 degreeC.

  In the mercury atomic fluorescence spectrometer 70 of the first embodiment, the mercury collecting tube 1 is heated to 500 ° C. by the first purge. However, when the mercury measuring device 4 warms up, the mercury collecting tube 1 is heated to, for example, 500 ° C. Then you may stand by.

  According to the mercury atomic fluorescence spectrometer 70 of the first embodiment, the mercury collecting tube is heated to 300 ° C. to 800 ° C. at an appropriate timing, and a carrier gas is allowed to flow through the mercury collecting tube for purging. Immediately after the mercury atomic fluorescence analyzer 70 is turned on or after a long waiting time, no matter what time the measurement starts, there is no decrease in sensitivity, and highly accurate analysis can be performed.

  The mercury atomic fluorescence analyzer 80 according to the second embodiment of the present invention will be described below. As shown in FIG. 1, this mercury atom fluorescence analyzer 80 differs from the mercury atom fluorescence analyzer 70 of the first embodiment only in the control means 30, and the other configuration is the same. At the time of the purge measurement setting set in the control means 30, the control means 30 controls the heating vaporization means 2, the open / close electromagnetic valve V1, and the three-way electromagnetic valve V2 so that the mercury collecting tube 1 is kept at the same temperature as the sample measurement. The purge measurement is performed at least once, for example, twice, for example, by flowing argon gas G1, which is the carrier gas G having the same flow rate as the sample measurement, into the mercury collecting tube 1 while heating. The control means 30 is provided in the computer 6, for example, and the control means 30 controls the entire mercury atomic fluorescence analyzer 80 including the mercury measuring device 4, the mass flow controller 5, and the pump P.

  The operation of the mercury atomic fluorescence analyzer 80 of the second embodiment will be described. FIG. 4 is a schematic flow diagram of the operation of the mercury atomic fluorescence analyzer 80, with an emphasis on purge measurement. When the mercury atomic fluorescence analyzer 80 is turned on, it enters a standby state like the mercury atomic fluorescence analyzer 70. Further, the control means 30 is set so that the purge measurement is performed twice, with the start of measurement after the mercury atomic fluorescence analyzer 80 is turned on as the purge measurement setting (when the first purge measurement is set). The heating temperature of the mercury collecting tube 1 in the standby state is the same as the heating temperature when the mercury in the sample gas S is collected by the mercury collecting agent 11 of the mercury collecting tube 1. In the purge measurement, a purge sample corresponding to a blank sample is measured, but the measured value is not used for quantitative analysis. Purge measurement is performed to purge the mercury collection tube 1 and the second purge carrier gas flow path.

  In the standby state, the control means 30 controls the heating and vaporizing means 2 so that the heating temperature of the mercury collecting tube 1 is set to 150 ° C., for example, and the mass flow controller 5 is closed and closed (the argon gas G1 does not flow). The electromagnetic valve V1 is opened and the pump P is driven to introduce air around the mercury atomic fluorescence spectrometer through a mercury removal filter (not shown) from the sample introduction port C1. At this time, the introduced air is an open / close electromagnetic valve V1, a branch path C3, a mercury collecting pipe 1 heated to 150 ° C., a branch path C4, a three-way electromagnetic valve V2, a flow rate adjusting valve V3, a pump P, and a discharge port C5. It flows in the order. The flow rate of the introduced air is adjusted to 0.5 L / min by the flow rate adjusting valve V3, and is introduced for 5 minutes, for example. The substance collected in the mercury collecting agent 11 through which the air introduced for 5 minutes has passed is used as the first purge sample.

  When the introduction of air is completed, the air that has flowed into the carrier gas flow path is replaced with argon gas G1 as in the case of the mercury atomic fluorescence spectrometer 70 of the first embodiment of the present invention. After this argon gas replacement is performed, the first purge measurement is started. When the first purge measurement is started, the mercury collecting tube 1 is heated to 500 ° C. by the heating vaporization means 2, and the first purge sample is supplied to the mercury measuring device 4 by the argon gas G1 introduced from the argon gas inlet C2. The sample is carried and measured. Argon gas G1 during sample measurement flows through the second purge carrier gas flow path. The argon gas G1 is adjusted to 0.1 L / min by the mass flow controller 5. The purge measurement time is, for example, 30 seconds.

  Similarly to the first purge sample, air around the mercury atomic fluorescence spectrometer is introduced, a second purge sample is generated, and a second purge measurement is performed.

  By the first purge measurement and the second purge measurement, the second purge carrier gas channel is purged, and the air and moisture (humidity) that have entered the carrier gas channel while the mercury atomic fluorescence analyzer 80 is turned off are purged. The Particularly, in the first purge measurement and the second purge measurement, the mercury collecting tube 1 is purged with the argon gas G1 as the carrier gas G during the sample measurement while being heated to 500 ° C. In the mercury collecting agent 11 filled in the mercury collecting tube 1 during the off period, the air and moisture that enter the gaps between the gold nanoparticles, the porous diatomaceous earth pores, the diatomaceous earth particles, and the like are efficient. Well kicked out.

  When the second purge measurement is completed, the control means 3 monitors the time from the end of the second purge measurement to the start of measurement as a standby time. The control means 3 is configured to perform the purge measurement of the mercury collecting tube 1 by setting the time before the start of the measurement after the purge unnecessary time set in the control means 3 has elapsed to the time of setting the purge measurement (when setting the second purge measurement). Is set. Before the start of measurement, the control means 3 determines whether or not the standby time exceeds a purge unnecessary time, for example, 1 hour. If the standby time exceeds 1 hour, the first purge measurement, the first purge is performed again. Two purge measurements are taken.

  If the waiting time is within one hour, mercury in the sample gas S is collected in the mercury collecting agent 11 and the sample measurement is started in the same manner as the mercury atomic fluorescence analyzer 70 of the first embodiment of the present invention. The

  When the measurement is completed, the control means 30 monitors the time from the end of the measurement to the start of the next measurement as a standby time. It is set in the control means 30 so that the purge measurement is performed twice with the time before the start of measurement after the purge measurement unnecessary time set in the control means 30 has elapsed as the purge measurement setting time (when the third purge measurement is set). ing. Before the start of the next measurement, the control means 30 determines whether or not the standby time exceeds a purge measurement unnecessary time, for example, 1 hour. If it is within 1 hour, the next measurement is started.

  If the standby time exceeds 1 hour, the first measurement and the second purge measurement are performed, and then the next measurement is started.

  FIG. 5 shows measurement data when the measurement is started after the first and second purge measurements are made after waiting for 17 hours. FIG. 5 shows measurement data of measurement peaks obtained by measuring the measurement peaks B1 and B2 of the first and second purge measurements and the same sample gas S three times. The three measurement peaks of the sample gas S after the first and second purge measurements show the same height, and it can be seen that the sensitivity is not lowered. Thus, even after waiting for 17 hours, a highly accurate analysis can be performed by the first and second purge measurements.

  FIG. 6 is an enlarged view of the measurement data of FIG. 5 by 100 times. FIG. 6 shows the measurement peaks B1 and B2 of the first and second purge measurements that were not visible in FIG. 5 before the enlargement. The measurement peaks B1 and B2 of the first and second purge measurements are considered to be peaks generated by mercury remaining in the second purge carrier gas channel. Mercury remaining in the second purge carrier gas flow path is removed by the first purge measurement, and the measurement peak of the second purge measurement is considerably lower than the measurement peak of the first purge measurement. Thus, the purge measurement has a secondary effect that can confirm the degree of contamination of the carrier gas channel.

  In the mercury atomic fluorescence analyzer 80 according to the second embodiment of the present invention, the first to third purge measurement setting times are set in the control means 3 as the purge measurement setting time. Any one or two at the time of setting the third purge measurement may be used. Four or more purge measurements may be set.

  In the mercury atomic fluorescence analyzer 80 according to the second embodiment of the present invention, the mercury collecting tube 1 is heated to 500 ° C. in the first purge measurement, but when the mercury measuring device 4 warms up, the mercury collecting tube 1 is You may stand by heating to 500 ° C.

  According to the mercury atomic fluorescence analyzer 80 of the second embodiment of the present invention, the mercury collecting tube is heated to the same temperature as when measuring the sample at an appropriate timing, and the same flow rate as when measuring the sample is passed through the mercury collecting tube. Since the purge measurement for flowing the carrier gas is performed at least once, the same operation and effect as the mercury atomic fluorescence analyzer 70 of the first embodiment of the present invention can be achieved.

  In the mercury atomic fluorescence analyzer 80 according to the second embodiment of the present invention, the heating temperature of the mercury collecting tube 1 in the standby state and the heating temperature of the mercury collecting tube 1 when collecting the mercury in the sample gas S are 150 ° C. However, it is not limited to this heating temperature, and if the heating temperature exceeds 200 ° C., the mercury collecting efficiency of the mercury collecting tube 1 decreases, so that the heating temperature is in the range of 150 ° C. to 200 ° C. Good. In addition, although the heating temperature of the mercury collecting tube 1 at the time of the first purge measurement, the second purge measurement, and the sample measurement is set to 500 ° C., it is not limited to this heating temperature, and the heating temperature is less than 300 ° C. If it exists, since the vaporization efficiency of mercury collected by the mercury collecting agent 11 is lowered, the heating temperature may be in the range of 300 ° C to 800 ° C. That is, the heating temperature of the mercury collecting tube 1 at the time of the first purge measurement and the second purge measurement is preferably heated to the same temperature as at the time of sample measurement.

  In the mercury atom fluorescence analyzers 70 and 80 of the first and second embodiments of the present invention, the apparatus for measuring atmospheric mercury has been described. However, the mercury atom fluorescence analyzers 70 and 80 for measuring atmospheric mercury are limited. Not a waste incinerator or thermal power reactor, but a mercury atomic fluorescence analyzer that measures mercury in flue exhaust gas and a reductive vaporizer that generates mercury gas by the reductive vaporization method. It may be a mercury atom fluorescence analyzer that measures mercury, a mercury atom fluorescence analyzer that includes a heat decomposition apparatus and measures the mercury in the sample by thermally decomposing the sample.

  In the mercury atomic fluorescence spectrometers 70 and 80 of the first and second embodiments of the present invention, the control means 3 and 30 are first to third at the time of purge setting or purge measurement setting set in the control means 3 and 30, respectively. The purge and the first to third purge measurements are performed, but the display unit (not shown) provided in the computer 6 displays that the first to third purges and the first to third purge measurements are performed, The measurer may perform the first to third purge and the first to third purge measurements according to the display.

  Here, what the inventor discovered in the process leading to the present invention will be described below. When the relationship between the decrease in sensitivity and the standby time was examined, the results shown in FIG. 7 were obtained. The horizontal axis in FIG. 7 is the waiting time (min). The vertical axis represents the relative value (%) of the sensitivity at each standby time, and the sensitivity when measured without the standby time is 100%. As can be seen from this figure, when the standby time exceeds 1 hour, the sensitivity decreases, and when it reaches 4 hours, the sensitivity decreases nearly 10%. When the degree of influence of air on the sensitivity reduction was examined, the result shown in FIG. 8 was obtained. The horizontal axis of FIG. 8 is the air content rate (volume%) in the argon gas, the vertical axis is the relative value (%) of the sensitivity, and the sensitivity when the air content rate in the argon gas is 0% is 100%. . It can be seen from FIG. 8 that when 1% of air is mixed in the argon gas, the relative sensitivity value is reduced to about 64%. When the degree of influence of moisture (humidity) on the sensitivity reduction was examined, it was found that when the moisture content in the argon gas was 4%, the relative value of sensitivity decreased to about 35%. Thus, it was found that the cause of the sensitivity decrease was air and moisture (humidity) mixed in the carrier gas flow paths of the mercury atomic fluorescence analyzers 70 and 80.

  Therefore, Experiments A to C were conducted in order to investigate the cause of the sensitivity decrease. In Experiment A, after waiting for 2 hours after the completion of the previous measurement, the second purge carrier gas flow path was purged with argon gas G1 at a flow rate of 0.4 L / min for 180 seconds while the mercury collection tube 1 was heated to 150 ° C. Thereafter, the same sample gas S was measured three times. The experiment A data is shown in FIG. In Experiment B, after waiting for 2 hours after the end of the previous measurement, the second purge carrier gas channel was not purged with argon gas G, and the mercury collecting tube 1 was heated to 500 ° C., and then the same sample gas S was measured three times. . The experimental B data is shown in FIG. In Experiment C, after waiting for 2 hours after the end of the previous measurement, the second purge carrier gas flow path was purged with argon gas G1 at a flow rate of 0.4 L / min for 180 seconds while the mercury collection tube 1 was heated to 500 ° C. Thereafter, the same sample gas S was measured three times. The experimental C data is shown in FIG.

  Each of the first measurement peak (left measurement peak) after waiting for 2 hours in FIG. 9 (experiment A data) and FIG. 10 (experiment B data) is the second and third measurement peaks (center measurement peak, It is lower than the measurement peak on the right side), and it can be seen that the first measurement has decreased sensitivity. On the other hand, the first to third measurement peaks after waiting for 2 hours in FIG. 11 (experiment C data) have the same height, and it can be seen that none of the measurement peaks has decreased in sensitivity. Therefore, when the second purge carrier gas flow path is purged with the argon gas G1 while keeping the mercury collecting pipe 1 at 500 ° C., the air and moisture that have entered the carrier gas flow path during the standby time, and the mercury collecting pipe It can be seen that in the mercury scavenger 11 filled in 1, the air and moisture entering the gaps between the gold nanoparticles, the porous pores of the diatomaceous earth, the gaps between the diatomaceous earth particles, and the like were expelled efficiently.

  From the experiments A to C, the control means 3 controls the heating vaporization means 2 and the valves V1 and V2 to set the mercury collecting tube 1 to 300 ° C. to 800 ° C. at the time of purge setting set in the control means 3. In the invention of heating and purging the mercury collection tube 1 by flowing a carrier gas through the mercury collection tube 1 and the purge measurement set in the control device 30, the control means 30 includes the heating vaporization means 2 and the valve. By controlling V1 and V2, the mercury collecting tube 1 is heated to the same temperature as the sample measurement, and the purge measurement is performed at least once by flowing the carrier gas G at the same flow rate as the sample measurement to the mercury collecting tube 1 The invention could be conceived.

  In the first and second embodiments of the present invention described above, the wavelength non-dispersion type mercury atom fluorescence analyzers 70 and 80 are shown. However, in the present invention, the wavelength dispersion type mercury atom fluorescence analyzer is shown. Also good.

DESCRIPTION OF SYMBOLS 1 Mercury collection pipe 2 Heating vaporization means 3, 30 Control means 4 Mercury measuring instrument 11 Mercury collection agent 70, 80 Mercury atomic fluorescence analyzer G Carrier gas S Sample gas V1 Opening and closing electromagnetic valve V2 Three-way electromagnetic valve

Claims (6)

A mercury collecting tube filled with a mercury collecting agent for collecting mercury in the sample gas;
Heating and vaporizing means for heating the mercury collecting tube to vaporize mercury;
A mercury measuring device for quantifying mercury heated and vaporized by the heating vaporization means;
A valve provided in a carrier gas flow path through which the carrier gas flows;
Control means for controlling the heating and vaporizing means and the valve;
With
At the time of purge setting set in the control means, the control means controls the heating vaporization means and the valve to heat the mercury collecting tube to 300 ° C. to 800 ° C., and the mercury collecting tube A mercury atomic fluorescence analyzer for purging the mercury collecting tube by flowing a carrier gas into the apparatus. The mercury atomic fluorescence analyzer according to claim 1,
A mercury atomic fluorescence analyzer in which the purge is set before the start of measurement after power is supplied to the mercury atomic fluorescence analyzer. The mercury atomic fluorescence analyzer according to claim 1,
Mercury in which the control means monitors the time from the end of measurement until the start of the next measurement as a standby time, and the standby time before the start of measurement after the purge unnecessary time set in the control means has elapsed is set as the purge setting time Atomic fluorescence analyzer. A mercury collecting tube filled with a mercury collecting agent for collecting mercury in the sample gas;
Heating and vaporizing means for heating the mercury collecting tube to vaporize mercury;
A mercury measuring device for quantifying mercury heated and vaporized by the heating vaporization means;
A valve provided in a carrier gas flow path through which the carrier gas flows;
Control means for controlling the heating and vaporizing means and the valve;
With
At the time of the purge measurement set in the control means, the control means controls the heating vaporization means and the valve to heat the mercury collecting tube to the same temperature as the sample measurement, and to collect the mercury A mercury atomic fluorescence spectrometer that performs at least one purge measurement in which a carrier gas having the same flow rate as that of a sample is passed through a tube. In the mercury atomic fluorescence analyzer according to claim 4,
A mercury atomic fluorescence analyzer in which the purge measurement is set before the start of measurement after power is turned on to the mercury atomic fluorescence analyzer. In the mercury atomic fluorescence analyzer according to claim 4,
The control means monitors the time from the end of measurement until the start of the next measurement as a standby time, and the time before the start of measurement after the purge measurement unnecessary time set in the control means has elapsed is the time when the purge measurement is set. Mercury atomic fluorescence analyzer.

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