AU600194B2 - Assaying aluminium in drinking water - Google Patents
Assaying aluminium in drinking water Download PDFInfo
- Publication number
- AU600194B2 AU600194B2 AU30418/89A AU3041889A AU600194B2 AU 600194 B2 AU600194 B2 AU 600194B2 AU 30418/89 A AU30418/89 A AU 30418/89A AU 3041889 A AU3041889 A AU 3041889A AU 600194 B2 AU600194 B2 AU 600194B2
- Authority
- AU
- Australia
- Prior art keywords
- aluminium
- mixed liquid
- fluoride
- solution
- sample stream
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Ceased
Links
- 239000004411 aluminium Substances 0.000 title claims description 42
- 229910052782 aluminium Inorganic materials 0.000 title claims description 42
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims description 40
- 239000003651 drinking water Substances 0.000 title description 5
- 235000020188 drinking water Nutrition 0.000 title description 5
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 34
- 239000007788 liquid Substances 0.000 claims description 33
- 238000000034 method Methods 0.000 claims description 24
- 239000000243 solution Substances 0.000 claims description 23
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 22
- 150000002500 ions Chemical class 0.000 claims description 17
- -1 fluoride ions Chemical class 0.000 claims description 16
- 239000012086 standard solution Substances 0.000 claims description 10
- 239000002253 acid Substances 0.000 claims description 5
- 239000008139 complexing agent Substances 0.000 claims description 4
- 159000000013 aluminium salts Chemical class 0.000 claims description 3
- 229910000329 aluminium sulfate Inorganic materials 0.000 claims description 3
- 230000015572 biosynthetic process Effects 0.000 claims description 3
- 230000000536 complexating effect Effects 0.000 claims description 3
- 238000005259 measurement Methods 0.000 claims description 3
- 150000003839 salts Chemical class 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 2
- 238000011437 continuous method Methods 0.000 claims description 2
- 229910021645 metal ion Inorganic materials 0.000 claims description 2
- 239000012266 salt solution Substances 0.000 claims description 2
- 229940000425 combination drug Drugs 0.000 claims 1
- VTLYFUHAOXGGBS-UHFFFAOYSA-N Fe3+ Chemical compound [Fe+3] VTLYFUHAOXGGBS-UHFFFAOYSA-N 0.000 description 4
- 229910001447 ferric ion Inorganic materials 0.000 description 4
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 0.000 description 4
- 239000003643 water by type Substances 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 150000001450 anions Chemical class 0.000 description 3
- 230000002452 interceptive effect Effects 0.000 description 3
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- 229940037003 alum Drugs 0.000 description 2
- JLDSOYXADOWAKB-UHFFFAOYSA-N aluminium nitrate Chemical compound [Al+3].[O-][N+]([O-])=O.[O-][N+]([O-])=O.[O-][N+]([O-])=O JLDSOYXADOWAKB-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000011067 equilibration Methods 0.000 description 2
- 230000002572 peristaltic effect Effects 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 235000013024 sodium fluoride Nutrition 0.000 description 2
- 239000011775 sodium fluoride Substances 0.000 description 2
- 239000003929 acidic solution Substances 0.000 description 1
- 230000002547 anomalous effect Effects 0.000 description 1
- 229960005070 ascorbic acid Drugs 0.000 description 1
- 235000010323 ascorbic acid Nutrition 0.000 description 1
- 239000011668 ascorbic acid Substances 0.000 description 1
- 238000003556 assay Methods 0.000 description 1
- 239000000872 buffer Substances 0.000 description 1
- 230000009918 complex formation Effects 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000035622 drinking Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000013536 elastomeric material Substances 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 238000012163 sequencing technique Methods 0.000 description 1
- 239000007974 sodium acetate buffer Substances 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N31/00—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods
- G01N31/16—Investigating or analysing non-biological materials by the use of the chemical methods specified in the subgroup; Apparatus specially adapted for such methods using titration
- G01N31/166—Continuous titration of flowing liquids
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/18—Water
- G01N33/1813—Specific cations in water, e.g. heavy metals
Landscapes
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Food Science & Technology (AREA)
- Medicinal Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Molecular Biology (AREA)
- Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
Description
011 DATE 25/08/89 APPLN. ID 3048/9 30418 89
PCT
WA0JP DATE 28/09/89 PCT NUMBER PCT/GB89/00077 INTERNATIONAL APPLICATIf j pj DE El TENT COOPERATION TREATY (PCT) l S U4 -T (51) International Patent ClassificationW 4 (11) International Publication Number: WO 89/ 07266 GOIN 33/18 Al (43) International Publication Date: 10 IAugusti1989 (10.08.89) (21) International Application Number: PCT/GB389/00077 (74) Agent: NEWBY, John, Ross J.Y. G.W. Johnson, Furnival House, 14-18 igl Holborn, London WC1V (22) International Filing Date: 27 January 1989 (27,01,89) 6DE (GB3), (31) Priority Application Number: 8802069 (81) Designated States: AT (European patent), AU, BE (European patent), CH (European patentD (uo (32) Priority Date: 29 January 1988 (29.0 1,88) peani patent), DK, FR (European patent), GB, GB i (European patent), IT (European patent), JP, LU (33) Priority Counitry: GB (European patent), NL. (European patent), NO, SE (71) SECT VDN 3,14) DIRECTION SEE FOLIO NAM'E D1RECTC ANM4'-AC L-41.htnf I S t 4 1 C4 q for amending the (72) h1fA.r l en the receipt (75)1nyentors/.kpplicant§'U r Lh6 onlyJ.-UALI, 67-Gamenah~ments, GB]; 8 Canterbury Road, Exwick, Exeter, Devon EX4 ~C Gardens, The Green, lBroadclyst, Exeter, Devon EXS 3DX (GB), (54)Tltle;, ASSAYING AIJvIN1WUM IN DRINKING WATER (57) Abstract The aluminiumA content in a water supply Is determined by a method which involves formning the aluminium In a samnple stream or the water Into at complex with added iiluorlde and sensing the fluoride content electrically. Equipment for carrying out the Invention comprises means (10) to mix a~sample, stream (in 1) with a standard sodium fluoride solution (in warm It (it! 12) and sense the PD generated between electrodes (13 and 14), Solutions of known. aluminium conventradion can be drawn from- reservoirs and to calibrate the fluoride ion selective electrode (14).
WbO 89/07266 PCT/GB89/09077 ASSAYING ALUMINIUM IN DRINKING WATER Technical Field This invention is concerned with the determination of trace quantities of aluminium in a water supply.
Background Art The Commission of the European Economic Community has recommended to companies and authorities responsible for local drinking water supplies, that such waters should contain no more than 0.2 milligrams per litre of aluminium; this recommendation is likely to become a regulhtion by 1990. A considerable proportion of the water industry employs alum as a flocculent for the turbidity of raw water and users of alum are most at risk of infringing the recommendation, but for the entire water industry there remains the problem of continuously assaying the quality of the water released from water treatment works when such works are staffed by analysts, if at all, for only part of the twenty-four hours of each day.
Summary of the Invention This invention seeks to provide an improved method of and equipment for assaying the aluminium content in drinking water which w'ill reduce and at best solve the aforesaid problem.
According to the present invention an automated continuous method of assaying the aluminium content of water, comprises abstracting a sample stream from a stream of water, flowing an acid buffered standard active fluoride ion solution at a rate which is in constant proportion to the rate of flow of the sample stream, mixing the sample stream of water and the flowing solution to form a mixed liquid, imposing a standard temperature on the mixed WO 89/07266 PCT/GB89/00077 2 liquid, allowing active fluoride ions to form a complex with aluminium in the mixed liquid, flowing the mixed liquid into contact with a calibrated fluoride ion selective electrode and a reference electrode, sensing the potential difference between the said electrodes, and electronically computing the aluminium content of the sample from the sensed potential difference.
f Conveniently acid is added to an abstracted stream to bring the aluminium content into solution at a pH of around 2.0 following which the required sample stream is taken and mixed with the buffered fluoride ion solution.
Complexes in accordance with the generic formula [A (H 2 0) x)F (1) are formed when acidic solutions of aluminium and active fluoride ions are mixed. Below the pKa ,of hydrofluoric acid the complex is slow to form and anomalous reductions in the active fluoride ion concentrations arise from the formation of HF. Again, above pH 5.5, hydroxyl ions compete with fluoride ions to complex with aluminium and such ions may also cause a deterioration of the fluoride ion selective electrode. Hence the pr-ferred range of pHs employed in the process is 4.0 to 5.5 and the buffered standard solution is desirably chosen to maintain a narrow band cf pH within'that range. Preferably the band width is 4.5 to 5.0. The value of the numeral x in the generic formula given above, is determined experimentally, and should be about 2.1 in line with the expected predominance of the species [AI(H 2 0) 4 F2] at the preferred pH band, but in some waters containing an anion which competes with fluoride in complexing aluminium, the value of x will be less than 2. This result is, first of all, an indication of the presence or incursion of such an ion, which in itself may be useful. Should the concentration of the interfering anion be a constant feature of the water, the WO 89/07266 PCT/GB89/00077 3 experimentally determined value of x will be a constant and may be used in the assay of aluminium. Otherwise the interfering anion can be complexed into an inactive form.
The method of the invention requires a measurable residual active fluoride ion content in the mixed liquid following the formation of the aluminium complex and the linear response of the potential difference between the electrodes to the logarithm of the concentration of active fluoride ions is preserved when the residual concentration is greater than 0.2 milligrams per litre of such fluoride ions; below that concentration the linearity of the relationship is lost and the potential difference sensed no longer gives accurate determinations of aluminium content.
An active ion meter is the preferred instrument for sensing the potential difference -ppearing between the electrodes and translating the sensed value into a measure of the aluminium content of the sample. In common with some known ion meters, a. microprocessor is desirably incorporated to facilitate calibration and calculation of measurement parameters. Where such a microprocessor is present it can be used to control the automatic sequencing of valves in automated equipment provided to operate the method, as will be more fully described hereafter, The standard'temperature imposed on the mixed liquid is preferably above ambient temperature and is thus normally achieved by warming the mixed liquid. The complex forms more rapidly as the temperature rises and, at about 4500., the period needed to achieve equilibration of the complex is of the order of one minute at the preferred pH band.
The method of the invention preferably utilises periodic recalibration of the ion selective electrode and it is convenient for this recalibration to be carried out automatically. For such recalibration, a stream of a
II
i- PI- WO 89/07266 PCT/GB89/00077 4 standard solution of aluminium ions can be substituted for the sample stream in the method of the invention and the mixed liquid flow maintained across the electrodes until a steady potential difference is attained. The datum can then be logged in a suitable memory. Repeating the method wi'th a second standard solution of different aluminium content, identifies a second level of potential difference which can also be logged. Using logged data from two such measurements with known aluminium contents enables the slope of the linear relationship of the sensed potential difference to the logarithm of the concentration of active fluoride ions to be determined and the selective electrode is thereby recalibrated.
The reduction of the act've fluoride ion content of the mixed liquid due to complexation with aluminium, in the analytic or calibration mode of operation, causes an electropositive change in the potential of the fluoride ion selective electrode versus the reference electrode and that change is related to the concentration of aluminium as follows: where [Al)
V
V
2 V V
AE
[All 1 2 10 k 2) Vix is the concentration of aluminium in the sample stream; is the volume of the sample stream; is the volume of the buffered fluoride ion solution; is the number of fluoride ions in the complex molecule; is the electropositive change in the potential of the ion-selective electrode versus the reference electrode showing increases in [Al]; is theoretically 2.303 F but in practice is the experimentally determined slope of the linear E versus log plot.
-AE
and k
I
a_ 1 -:ir WO 89/07266 PCT/GB89/00077 With the exception of the variable -AE. the other values on the right-hand side of equation are constants of the eouioment and the method, so that equation (2) reduces to [A C. E (3) where C is a constant.
There are some waters which naturally contain ferric ion and as ferric ion also complexes with fluoride ion, the ferric ion should be rendered inactive before the aluminium determination is carried out. Complexing agents are available which will combine with ferric ion whilst not interfering with aluminium, and one example would be ascorbic acid. Therefore buffered fluoride solutions which also contain a ferric complexing agent are useful in carrying out the method of this invention, Equally there are waters which either naturally, or av a result of treatment, contain fluoride ions, In such cases it is essential to determine the inherent fluoride ion content by firstly complexing all trivalent metal ions with a non-fluoride complexing agent so that the fluoride content present when the potential difference is assessed consists entirely of the added active fluoride ions.
Ine invention also extends to automated assaying equipment for carrying out the method, and in this aspect comprises an active ion meter, a reference electrode and a calibrated fluoride ion selective electrode electrically connected via the ion meter, a first conduit adapted to cuiLain the sample stream, a second conduit adapted to conduct the buffered standard active fluoride solution, means to induce a constant rate of flow in each of the first and second conduits, a confluence of the first and second conduits adapted to allow the combination of the WO 89/07266 PCT/GB89/00077 6 sample stream and fluoride ion solution to form a mixed liquid, means to impose a standard temperature on the mixed liquid, means to conduct the mixed liquid into contact with the said electrodes, and means to record the EMF generated between said electrodes as determined by the ion meter.
For the purpose of recalibration of the fluoride ion selective electrode, the equipmern preferably also comprises two reservoirs adapted to contain, respectively, first and second standard solutions of an aluminium salt differing in salt concentration, valve means to control the flow of standard solution from each reservoir, a third conduit adapted to receive liquid from the valve means, a confluence of the third conduit with the second conduit, Valve means to control the entry of the sample stream into the first conduit and an automatic sequencer adapted to open the valve means in sequence for predetermined periods in such a way that only one of the sample stream, the first and the second standard aluminium salt solutions may flow I into the confluence with the second conduit at a time, It is convenient to use a common conduit for the 1 sample stream and the first and second standard aluminium solutions.
The conduits used in the equipment are preferably of small bore tubing to encourage linear flow therein and to minimise back-mixing. The preferred means to induce a ii constant rate of flow in each of the first and second conduits, is a peristaltic pump operating on both similarly sized conduits simultaneously. This requires that each conduit, at least over the length in contact with the pump, is made of an elastomeric material.
Suitably the means to impose a standard temperature on the mixed liquid includes a digester toil and one or more reactor coils all maintained at the desired temperature.
Conveniently the said means warms the mixed liquid to 450C L 1 i WO 89/07266 PCT/GB89/00077 7 for at least five minutes to ensure the equilibration of complex formation and, to this end, it is convenient that the conduit for the mixed liquid should be a helix or other labyrinthine structure within a heated member a heated fluid bath).
Brief Description of the Drawing The invention will now be more fully described, by way of example, with reference to the accompanying drawing, in which: 10 Figure 1 is a schematic block diagram of one embodiment of equipment for carrying out the method, and Figure 2 is a more detailed block diagram of a second embodiment of equipment according to the invention.
Description of Preferred Embodiments Referring to Figure 1, a conduit 1 is a side branch on a pipe 2 through which water to be sampled is flowing in the direction of the arrow A. Reservoirs 3 and 4 respectively contain different standard solutions of aluminium nitrate S 1 and S 2 (one may be devoid of aluminium and is then a zero standard solution) and are connected via valves and 6 with the conduit 1. Valve 7 in conduit 1 controls the flow of the stream of sampled water. Reservoir 8 contains a standard sodium fluoride solution, say 5 mil- J ligrams of fluoride ions per litre, buffered to a pH of between 4,5 and 5.0 with an acetic acid/sodium acetate buffer. Reservoir 8 is connected via conduit 9 with a confluence 10 where conduits 1 and 9 join. Conduits I and 9 pass collaterally through a peristaltic pump 11 upstream of the confluence 10 and as the conduits where they pass through the pump 11 are flexible tubes of identically sized bores, the effect of the pump 11 is to deliver equal volumes of liquids through the conduits 1 and 9 to the WO 89/07266 PCT/GB89/00077 8 confluence 10. Downstream of the confluence 10 the mixed liquid is contained in the conduit 1, passing through a heated block 12, which imposes a temperature of 450C on the mixed liquid, and into operative contact with a reference electrode 13 and a fluoride ion selective electrode 14, the electrodes 13 and 14 being electrically connected via an active ion meter 15. The active ion meter comprises a millivolt meter, and a microprocessor/rancom access memory circuit to cope, by known methods, with retaining the datum calibration voltages established experimentally and to carry out the calculation.
[All C. -AE Sfrom the change in the potential difference sensed between the electrodes 13 and 14 occasioned by variations in the aluminium content of the sampled drinking) water. The active ion meter 15 is electrically connected to a digital display 16 and a pen recorder 17 on both of which a direct reading of the concentration of aluminium in the sampled water is displayed.
i 20 For the convenience of confining the electronic circuitry to one box, the active ion meter 15 can also house a sequencer 18 arranged to control, via connections 19, the scheduled sequential opening and closing of valves 6 and 7 so that only one valve is open at any time.
With the valve 7 open, the equipment is in its analytic modi and the sample stream is metered by the pump 11 into contact with a metered flow of the buffered standard fluoride solution. The mixed liquid thus formed passes through the heated block 12, attaining a temperature of 45 0 C and shortly thereafter five minutes later) comes into operative contact with the electrodes 13 and 14.
Changes in the logarithm of concentration of aluminium in the sampled water are directly related to electropositive changes in the EMF appearing between the electrodes 13 and WO 89/07266 PCT/GB89/00077 9 14 and such changes are translated electronically into a direct read out on the recorder 17 of the aluminium concentration in the sampled water.
In its calibration mode, valve 7 is closed and valve is opened to allow the first standard aluminium solution S from reservoir 3 to enter the conduit 1 where within a short interval it displaces the residue of the sample stream. The remainder of the process remains unchanged with the exception that by the time a steady signal characteristic of the mixed calibrating liquid has been established, the correlation of a known aluminium content and the experimentally determined EMF are transferred as a datum to the electronic memory. Closing valve 5 and opening valve 6 allows the process to be repeated with the second standard aluminium solution S 2 providing a second datum for transfer to the memory, These data determine the slope, k of the linear relationship set forth in equation 2 above. At the completion of the calibration procedure, valve 6 is closed and valve 7 opened so that the analytic mode is reintroduced, Figure 2 shows a modified form of equipment and, where appropriate the same reference numerals as have been used in Figure 1 are employed. The main features of difference between the Fi, ure 1 and Figure 2 arrangements are: Reservoir 8 Is divided into a tank 8A for acid and a tank 8B for buffer.
The pump 11 is shown as two linked pumps 11A and 11B, A digester coil 20, a reactor coil 21 and a cell 22 are immersed in a common heated water bath 23, An interface output 24 to RS 232) is provided on the meter
Claims (8)
1. An automated continuous method of assaying the aluminium content of water, which comprises abstracting a sample stream from a stream of water, flowing an acid buffered standard active fluoride ion solution at a rate which is in constant proportion to the rate of flow of the sample stream, mixing the sample stream of water and the flowing solution to form a mixed liquid, imposing a stan- dard temperature on the mixed liquid, allowing active fluoride ions to form a complex with aluminium in the mixed liquid, flowing the mixed liquid into contact with a calibrated fluoride ion selective electrode and a reference electrode, sensing the potential difference between the said electrodes, and electronically computing the aluminium content of the sample from the sensed potential difference,
2. A method as claimed in claim 1, characterised in that acid is added to the abstracted stream to bring the aluminium content into solution at a pH of around following which the required sample stream is taken and mixed with the buffered fluoride ion solution.
3. A method as claimed in claim 1, characterised in that the pH of the mixed liquid is in the range 4.0 to 53,,
4. A method as claimed in claim 3, characterised in that the residual active fluoride ion content in the mixed liquid following the formation of the aluminium complex is greater than 0.2 milligrams per litre of such fluoride ions, A method as claimed in claim 4, characteriset in that the mixed liquid is warmed to a predetermined tempera- ture prior to the sensing of the potential difference,
6. A method as claimed in claim 5, characterised in ii II Vo 89/07266 PCT/GB89/000077 11 that the ion selective electrode is periodically calibrated using a first standard solution of aluminium ions sub- stituted for the sample stream to give a first recalihra- tion potential difference and then a second stanaard solution of different alumnnium content to give a second recalibration potential difference, data from said two measurements, with known aluminium contents enabling the selective electrode to thereby be recalibrated,
7. A method as claimed in claim 5, characterised in that a buffered fluoride solution which also contains a ferric complexin9 agent is used to form the mixed liquid,
8. A method as claimed in claim 5, characterised in that the inherent fluoride ion content of the sample stream is determined by firstly complexing all trivalent metal ions with a non-fluoride complexing agent so that the fluoride content present when the potential difference is assessed consists entirely of the added active fluoride ions.
9. Automated assaying equipment for carrying out the method of claim 1, which comprises an active ion meter, a reference electrode and a calibrated fluoride ion selective electrode electrically connected via the ion meter, a first conduit adapted to contain the sample stream, a second conduit adapted to conduct the buffered standard active fluoride solution, means to induce a constant rate of flow in each of the first and second conduits, a confluence of the first and second conduits adapted to allow the combina- tion of the sample stream and fluoride ion solution to form a mixed liquid, means to impose a standard temperature on the mixed liquid, means to conduct the mixed liquid into contact with the said electrodes, and means to record the EMF generated between said electrodes as determined by the ion meter, Equi:, nt as claimed in claim 9, characterised in i r L WO 89/07266 PCT/GB89/00077 12 that the equipment also comprises two reservoirs adapted to contain, respectively, first and second standard solutions of an alumini.m salt differing in salt concentration, valve means to control the flow of standard solution from each reservoir, a third conduit adapted to receive liquid from the valve means, a confluence of the third conduit with the second conduit, valve means to control the entry of the sample stream into the first conduit and an automatic sequencer adapted to open the valve means in sequence for predetermined periods in such a way that only one of the sample stream, the first and the second standard aluminium salt solutions may flow into the confluence with the second conduit at a timne. it i3
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB888802069A GB8802069D0 (en) | 1988-01-29 | 1988-01-29 | Assaying aluminium in drinking water |
| GB8802069 | 1988-01-29 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU3041889A AU3041889A (en) | 1989-08-25 |
| AU600194B2 true AU600194B2 (en) | 1990-08-02 |
Family
ID=10630775
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU30418/89A Ceased AU600194B2 (en) | 1988-01-29 | 1989-01-27 | Assaying aluminium in drinking water |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0352319A1 (en) |
| AU (1) | AU600194B2 (en) |
| DK (1) | DK463389A (en) |
| GB (1) | GB8802069D0 (en) |
| WO (1) | WO1989007266A1 (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1574225A (en) * | 1976-05-29 | 1980-09-03 | Hoechst Ag | Quantitative analysis of aluminium/carbon and aluminium/hydrogen bonds |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CH597901A5 (en) * | 1975-01-23 | 1978-04-14 | Aligena Ag | |
| FR2524641A1 (en) * | 1982-04-01 | 1983-10-07 | Lyonnaise Eaux Eclairage | Appts. to prepare samples of water e.g. from treatment plant - by adsorption on column packing for subsequent elution and analysis |
-
1988
- 1988-01-29 GB GB888802069A patent/GB8802069D0/en active Pending
-
1989
- 1989-01-27 WO PCT/GB1989/000077 patent/WO1989007266A1/en not_active Application Discontinuation
- 1989-01-27 EP EP19890902062 patent/EP0352319A1/en not_active Ceased
- 1989-01-27 AU AU30418/89A patent/AU600194B2/en not_active Ceased
- 1989-09-20 DK DK463389A patent/DK463389A/en not_active Application Discontinuation
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1574225A (en) * | 1976-05-29 | 1980-09-03 | Hoechst Ag | Quantitative analysis of aluminium/carbon and aluminium/hydrogen bonds |
Also Published As
| Publication number | Publication date |
|---|---|
| GB8802069D0 (en) | 1988-02-24 |
| DK463389D0 (en) | 1989-09-20 |
| EP0352319A1 (en) | 1990-01-31 |
| WO1989007266A1 (en) | 1989-08-10 |
| DK463389A (en) | 1989-09-20 |
| AU3041889A (en) | 1989-08-25 |
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