I just bought one of those Titrets kits by Chemetrics that came with a
"holder" The instructions do not say how the holder works or how to use it.
I have never used a Titret before, have no chemistry background and would
like some guidance from the group on how to use the holder, and the Titret
in terms of tips on using them.

Another question: Lum states in his e-book The Home WineMakers Manual that:


"Winemakers try to maintain 20 to 40 milligrams per liter of free SO2 in
their wine from the completion of fermentation until the wine is
bottled, but the amount of free SO2 does not remain constant."

If you know that the S02 level is going to drop, why not compensate somewhat
in the beginning by adjusting to more than 20 to 40?

The wine I am measuring is a Chenin Blanc from Alexander's Sun Country
concentrate in its final stages. Should the s02 level at bottling be
between 20 and 30? Will that value be read directly off of the Titret?

Thanks for reading,

____

KB
St. Charles, MO

p.s. I did searches on Jack Keller's site http://winemaking.jackkeller.net
, Google, Groups and Lum E's book http://home.att.net/~lumeisenman/ but no
cigar.

"K. B." > wrote in message om>...
> I just bought one of those Titrets kits by Chemetrics that came with a
> "holder" The instructions do not say how the holder works or how to use it.
> I have never used a Titret before, have no chemistry background and would
> like some guidance from the group on how to use the holder, and the Titret
> in terms of tips on using them.
<<snip>>
> KB


KB -
Check out this page from the Chemetrics web site:

http://www.chemetrics.com/titrets.html

I agree, the instructions that come with the Titrets kits are a bit
minimal; I think they must figure most buyers are already familiar
with them. The critical piece is that they are made with a partial
vacuum in the glass tube. When you press the lever on the "holder",
that allows some of the wine to be sucked up through the tube into the
body of the titret. Hence, the important thing is to keep the open
end of the little tube in the wine (so you get wine, not air) and do
several very short squeezes of the lever, so that you don't overshoot
the color change point. As indicated on the web site, the resulting
measurement is obtained by reading the fluid level vs the scale
printed on the side of the tube. The numbers on the scale run from
about 10 to 100, and the Titrets package indicates that the
measurement range is from 10 to 100 mg/L.

In terms of how much SO2 is enough, the precise level isn't really
critical, and unless you are planning on extended bottle aging,
anything within a pretty broad range will probably be OK.

As you indicated, most sources tell you to measure periodically and
adjust the level, rather than adding all of it up front. I think
there are two good reasons for this. First, although SO2
concentrations do tend to drop over time, how much/how fast will vary.
So there is no precise way to know in advance precisely how much you
will need. Second, even if you could predict the total SO2 required
over the wine's lifetime, you probably wouldn't want to add all of it
in one bit dose up front, as it might inhibit the yeast, would
interfere with things like MLF, and might cause other undesirable
effects. Your wine would be over-sulfited during fermentation and
most of its aging, in order to reach the "right" level at the end of
the whole process. It might work out well enough, but it doesn't
sound to me like an approach that is going to produce the best
possible end result. That's my two cents.

Happy fermenting -

Doug

"K. B." > wrote in message om>...
> I just bought one of those Titrets kits by Chemetrics that came with a
> "holder" The instructions do not say how the holder works or how to use it.
> I have never used a Titret before, have no chemistry background and would
> like some guidance from the group on how to use the holder, and the Titret
> in terms of tips on using them.
<<snip>>
> KB


KB -
Check out this page from the Chemetrics web site:

http://www.chemetrics.com/titrets.html

I agree, the instructions that come with the Titrets kits are a bit
minimal; I think they must figure most buyers are already familiar
with them. The critical piece is that they are made with a partial
vacuum in the glass tube. When you press the lever on the "holder",
that allows some of the wine to be sucked up through the tube into the
body of the titret. Hence, the important thing is to keep the open
end of the little tube in the wine (so you get wine, not air) and do
several very short squeezes of the lever, so that you don't overshoot
the color change point. As indicated on the web site, the resulting
measurement is obtained by reading the fluid level vs the scale
printed on the side of the tube. The numbers on the scale run from
about 10 to 100, and the Titrets package indicates that the
measurement range is from 10 to 100 mg/L.

In terms of how much SO2 is enough, the precise level isn't really
critical, and unless you are planning on extended bottle aging,
anything within a pretty broad range will probably be OK.

As you indicated, most sources tell you to measure periodically and
adjust the level, rather than adding all of it up front. I think
there are two good reasons for this. First, although SO2
concentrations do tend to drop over time, how much/how fast will vary.
So there is no precise way to know in advance precisely how much you
will need. Second, even if you could predict the total SO2 required
over the wine's lifetime, you probably wouldn't want to add all of it
in one bit dose up front, as it might inhibit the yeast, would
interfere with things like MLF, and might cause other undesirable
effects. Your wine would be over-sulfited during fermentation and
most of its aging, in order to reach the "right" level at the end of
the whole process. It might work out well enough, but it doesn't
sound to me like an approach that is going to produce the best
possible end result. That's my two cents.

Happy fermenting -

Doug

"Doug" > wrote in message
om...
> "K. B." > wrote in message
om>...
> > I just bought one of those Titrets kits by Chemetrics that came with a
> > "holder" The instructions do not say how the holder works or how to use
it.
> > I have never used a Titret before, have no chemistry background and
would
> > like some guidance from the group on how to use the holder, and the
Titret
> > in terms of tips on using them.
> <<snip>>
> > KB
>
>
> KB -
> Check out this page from the Chemetrics web site:
>
> http://www.chemetrics.com/titrets.html
>
> I agree, the instructions that come with the Titrets kits are a bit
> minimal; I think they must figure most buyers are already familiar
> with them. The critical piece is that they are made with a partial
> vacuum in the glass tube. When you press the lever on the "holder",
> that allows some of the wine to be sucked up through the tube into the
> body of the titret. Hence, the important thing is to keep the open
> end of the little tube in the wine (so you get wine, not air) and do
> several very short squeezes of the lever, so that you don't overshoot
> the color change point. As indicated on the web site, the resulting
> measurement is obtained by reading the fluid level vs the scale
> printed on the side of the tube. The numbers on the scale run from
> about 10 to 100, and the Titrets package indicates that the
> measurement range is from 10 to 100 mg/L.
>
> In terms of how much SO2 is enough, the precise level isn't really
> critical, and unless you are planning on extended bottle aging,
> anything within a pretty broad range will probably be OK.
>
> As you indicated, most sources tell you to measure periodically and
> adjust the level, rather than adding all of it up front. I think
> there are two good reasons for this. First, although SO2
> concentrations do tend to drop over time, how much/how fast will vary.
> So there is no precise way to know in advance precisely how much you
> will need. Second, even if you could predict the total SO2 required
> over the wine's lifetime, you probably wouldn't want to add all of it
> in one bit dose up front, as it might inhibit the yeast, would
> interfere with things like MLF, and might cause other undesirable
> effects. Your wine would be over-sulfited during fermentation and
> most of its aging, in order to reach the "right" level at the end of
> the whole process. It might work out well enough, but it doesn't
> sound to me like an approach that is going to produce the best
> possible end result. That's my two cents.
>
> Happy fermenting -
>
> Doug


Thanks for the feedback Doug. After breaking the tip and placing it in the
wine sample, something came out of the tip and into the wine. That may be
normal- the web site indicated there was a starch solution in the tip. Is
it normal for that solution to (in the tip) to disperse into the sample?

The final reading was between 15 and 20, I drew sample in to fast (as you
warned about) and missed the exact end point. At least it gave me some
piece of mind as I had been bulk aging for some months.

KB

"Doug" > wrote in message
om...
> "K. B." > wrote in message
om>...
> > I just bought one of those Titrets kits by Chemetrics that came with a
> > "holder" The instructions do not say how the holder works or how to use
it.
> > I have never used a Titret before, have no chemistry background and
would
> > like some guidance from the group on how to use the holder, and the
Titret
> > in terms of tips on using them.
> <<snip>>
> > KB
>
>
> KB -
> Check out this page from the Chemetrics web site:
>
> http://www.chemetrics.com/titrets.html
>
> I agree, the instructions that come with the Titrets kits are a bit
> minimal; I think they must figure most buyers are already familiar
> with them. The critical piece is that they are made with a partial
> vacuum in the glass tube. When you press the lever on the "holder",
> that allows some of the wine to be sucked up through the tube into the
> body of the titret. Hence, the important thing is to keep the open
> end of the little tube in the wine (so you get wine, not air) and do
> several very short squeezes of the lever, so that you don't overshoot
> the color change point. As indicated on the web site, the resulting
> measurement is obtained by reading the fluid level vs the scale
> printed on the side of the tube. The numbers on the scale run from
> about 10 to 100, and the Titrets package indicates that the
> measurement range is from 10 to 100 mg/L.
>
> In terms of how much SO2 is enough, the precise level isn't really
> critical, and unless you are planning on extended bottle aging,
> anything within a pretty broad range will probably be OK.
>
> As you indicated, most sources tell you to measure periodically and
> adjust the level, rather than adding all of it up front. I think
> there are two good reasons for this. First, although SO2
> concentrations do tend to drop over time, how much/how fast will vary.
> So there is no precise way to know in advance precisely how much you
> will need. Second, even if you could predict the total SO2 required
> over the wine's lifetime, you probably wouldn't want to add all of it
> in one bit dose up front, as it might inhibit the yeast, would
> interfere with things like MLF, and might cause other undesirable
> effects. Your wine would be over-sulfited during fermentation and
> most of its aging, in order to reach the "right" level at the end of
> the whole process. It might work out well enough, but it doesn't
> sound to me like an approach that is going to produce the best
> possible end result. That's my two cents.
>
> Happy fermenting -
>
> Doug


Thanks for the feedback Doug. After breaking the tip and placing it in the
wine sample, something came out of the tip and into the wine. That may be
normal- the web site indicated there was a starch solution in the tip. Is
it normal for that solution to (in the tip) to disperse into the sample?

The final reading was between 15 and 20, I drew sample in to fast (as you
warned about) and missed the exact end point. At least it gave me some
piece of mind as I had been bulk aging for some months.

KB

Nothing should come out of the tip into the wine sample. Did you slide the
rubber tube with the valve all the way onto the ampule (to the white line)
before snapping the end of the ampule? Yes there's a starch solution in the
ampule, but it shouldn't come out due to the vacuum in the ampule.

Ed

> Thanks for the feedback Doug. After breaking the tip and placing it in
the
> wine sample, something came out of the tip and into the wine. That may be
> normal- the web site indicated there was a starch solution in the tip. Is
> it normal for that solution to (in the tip) to disperse into the sample?
>
> The final reading was between 15 and 20, I drew sample in to fast (as you
> warned about) and missed the exact end point. At least it gave me some
> piece of mind as I had been bulk aging for some months.
>
> KB
>
>

Nothing should come out of the tip into the wine sample. Did you slide the
rubber tube with the valve all the way onto the ampule (to the white line)
before snapping the end of the ampule? Yes there's a starch solution in the
ampule, but it shouldn't come out due to the vacuum in the ampule.

Ed

> Thanks for the feedback Doug. After breaking the tip and placing it in
the
> wine sample, something came out of the tip and into the wine. That may be
> normal- the web site indicated there was a starch solution in the tip. Is
> it normal for that solution to (in the tip) to disperse into the sample?
>
> The final reading was between 15 and 20, I drew sample in to fast (as you
> warned about) and missed the exact end point. At least it gave me some
> piece of mind as I had been bulk aging for some months.
>
> KB
>
>

"Ed Marks" > wrote in message
...
> Nothing should come out of the tip into the wine sample. Did you slide
the
> rubber tube with the valve all the way onto the ampule (to the white line)
> before snapping the end of the ampule? Yes there's a starch solution in
the
> ampule, but it shouldn't come out due to the vacuum in the ampule.
>
> Ed
>


I slid the tube all the way over the ampule and then snapped. When I placed
the tube in the sample, before squeezing the tube, you could see the mixing
of the contents of the tube with the sample. However, the ampule turned
almost black, and stayed that way until about the 10 marking on the ampule
(it then started to fade). At 15 it was almost back to the original color of
the sample. Something did definitely come out of the end into the sample.
Is the test still valid?

KB

I have no idea - but your observation made me go back and look at the titret
information sheet. I really hadn't paid attention to whether there was
anything in the valve assemble that you put onto the ampule, and found out
there is. Supposedly it has approximately .05 ml of phosphoric acid - which
I can see in the harder plastic tube ahead of the valve. I assume this
needs to get into the ampule when you press on the valve, to acidify the
wine sample that goes into the ampule and release the SO2 to react with the
reagents in the ampule. If, for some reason, the phosphoric acid is going
out of the valve assembly rather than into the ampule, you are probably not
getting an accurate test result - unless Chemetrics assumes a small amount
will come out and it doesn't matter. That's my interpretation at least -
why don't you send an e-mail to Chemetrics
(http://www.chemetrics.com/contact.html and select "Technical Questions")
and see what they say. If you do that, please share what you hear from
them.

Ed



"K. B." > wrote in message
...
>
>
> "Ed Marks" > wrote in message
> ...
> > Nothing should come out of the tip into the wine sample. Did you slide
> the
> > rubber tube with the valve all the way onto the ampule (to the white
line)
> > before snapping the end of the ampule? Yes there's a starch solution in
> the
> > ampule, but it shouldn't come out due to the vacuum in the ampule.
> >
> > Ed
> >
>
>
> I slid the tube all the way over the ampule and then snapped. When I
placed
> the tube in the sample, before squeezing the tube, you could see the
mixing
> of the contents of the tube with the sample. However, the ampule turned
> almost black, and stayed that way until about the 10 marking on the ampule
> (it then started to fade). At 15 it was almost back to the original color
of
> the sample. Something did definitely come out of the end into the sample.
> Is the test still valid?
>
> KB
>
>

I have no idea - but your observation made me go back and look at the titret
information sheet. I really hadn't paid attention to whether there was
anything in the valve assemble that you put onto the ampule, and found out
there is. Supposedly it has approximately .05 ml of phosphoric acid - which
I can see in the harder plastic tube ahead of the valve. I assume this
needs to get into the ampule when you press on the valve, to acidify the
wine sample that goes into the ampule and release the SO2 to react with the
reagents in the ampule. If, for some reason, the phosphoric acid is going
out of the valve assembly rather than into the ampule, you are probably not
getting an accurate test result - unless Chemetrics assumes a small amount
will come out and it doesn't matter. That's my interpretation at least -
why don't you send an e-mail to Chemetrics
(http://www.chemetrics.com/contact.html and select "Technical Questions")
and see what they say. If you do that, please share what you hear from
them.

Ed



"K. B." > wrote in message
...
>
>
> "Ed Marks" > wrote in message
> ...
> > Nothing should come out of the tip into the wine sample. Did you slide
> the
> > rubber tube with the valve all the way onto the ampule (to the white
line)
> > before snapping the end of the ampule? Yes there's a starch solution in
> the
> > ampule, but it shouldn't come out due to the vacuum in the ampule.
> >
> > Ed
> >
>
>
> I slid the tube all the way over the ampule and then snapped. When I
placed
> the tube in the sample, before squeezing the tube, you could see the
mixing
> of the contents of the tube with the sample. However, the ampule turned
> almost black, and stayed that way until about the 10 marking on the ampule
> (it then started to fade). At 15 it was almost back to the original color
of
> the sample. Something did definitely come out of the end into the sample.
> Is the test still valid?
>
> KB
>
>

Thank you, I did write using the link you provided and will post the reply!

KB
Saint Charles County, Missouri


"Ed Marks" > wrote in message
...
> I have no idea - but your observation made me go back and look at the
titret
> information sheet. I really hadn't paid attention to whether there was
> anything in the valve assemble that you put onto the ampule, and found out
> there is. Supposedly it has approximately .05 ml of phosphoric acid -
which
> I can see in the harder plastic tube ahead of the valve. I assume this
> needs to get into the ampule when you press on the valve, to acidify the
> wine sample that goes into the ampule and release the SO2 to react with
the
> reagents in the ampule. If, for some reason, the phosphoric acid is going
> out of the valve assembly rather than into the ampule, you are probably
not
> getting an accurate test result - unless Chemetrics assumes a small amount
> will come out and it doesn't matter. That's my interpretation at least -
> why don't you send an e-mail to Chemetrics
> (http://www.chemetrics.com/contact.html and select "Technical Questions")
> and see what they say. If you do that, please share what you hear from
> them.
>
> Ed
>
>
>
> "K. B." > wrote in message
> ...
> >
> >
> > "Ed Marks" > wrote in message
> > ...
> > > Nothing should come out of the tip into the wine sample. Did you
slide
> > the
> > > rubber tube with the valve all the way onto the ampule (to the white
> line)
> > > before snapping the end of the ampule? Yes there's a starch solution
in
> > the
> > > ampule, but it shouldn't come out due to the vacuum in the ampule.
> > >
> > > Ed
> > >
> >
> >
> > I slid the tube all the way over the ampule and then snapped. When I
> placed
> > the tube in the sample, before squeezing the tube, you could see the
> mixing
> > of the contents of the tube with the sample. However, the ampule turned
> > almost black, and stayed that way until about the 10 marking on the
ampule
> > (it then started to fade). At 15 it was almost back to the original
color
> of
> > the sample. Something did definitely come out of the end into the
sample.
> > Is the test still valid?
> >
> > KB
> >
> >
>
>

Thank you, I did write using the link you provided and will post the reply!

KB
Saint Charles County, Missouri


"Ed Marks" > wrote in message
...
> I have no idea - but your observation made me go back and look at the
titret
> information sheet. I really hadn't paid attention to whether there was
> anything in the valve assemble that you put onto the ampule, and found out
> there is. Supposedly it has approximately .05 ml of phosphoric acid -
which
> I can see in the harder plastic tube ahead of the valve. I assume this
> needs to get into the ampule when you press on the valve, to acidify the
> wine sample that goes into the ampule and release the SO2 to react with
the
> reagents in the ampule. If, for some reason, the phosphoric acid is going
> out of the valve assembly rather than into the ampule, you are probably
not
> getting an accurate test result - unless Chemetrics assumes a small amount
> will come out and it doesn't matter. That's my interpretation at least -
> why don't you send an e-mail to Chemetrics
> (http://www.chemetrics.com/contact.html and select "Technical Questions")
> and see what they say. If you do that, please share what you hear from
> them.
>
> Ed
>
>
>
> "K. B." > wrote in message
> ...
> >
> >
> > "Ed Marks" > wrote in message
> > ...
> > > Nothing should come out of the tip into the wine sample. Did you
slide
> > the
> > > rubber tube with the valve all the way onto the ampule (to the white
> line)
> > > before snapping the end of the ampule? Yes there's a starch solution
in
> > the
> > > ampule, but it shouldn't come out due to the vacuum in the ampule.
> > >
> > > Ed
> > >
> >
> >
> > I slid the tube all the way over the ampule and then snapped. When I
> placed
> > the tube in the sample, before squeezing the tube, you could see the
> mixing
> > of the contents of the tube with the sample. However, the ampule turned
> > almost black, and stayed that way until about the 10 marking on the
ampule
> > (it then started to fade). At 15 it was almost back to the original
color
> of
> > the sample. Something did definitely come out of the end into the
sample.
> > Is the test still valid?
> >
> > KB
> >
> >
>
>

I wrote chemetrics as suggested and asked the following questions:
1) Is it normal for liquid to appear at the titret tip after snapping
the score?
2) Is it normal for liquid from the titret to enter the wine sample?
3) Will the results be accurate (in this case 15 mg/l was indicated).

Here is Chemetrics Response:

<<It is not unusual for a drop or two of the valve assembly's content to be
lost
when the valve assembly is attached to the ampoule, or when the ampoule is
snapped at the score mark. This is not a problem if only a drop of the
assembly's contents is dispensed into the sample prior to its introduction
into
the test ampoule. However, the majority of the assembly's content should
enter
the test ampoule, so if all or most of the assembly's content enters the
sample
prior to beginning testing or is otherwise lost ,this is a problem.

As long as the user sees the blue color in the test ampoule, all is well.

I hope this helps. Please let me know if you have additional questions.

Regards,


Technical Services
Chemetrics, Inc.
ph: 540-788-9026
fax: 540-788-4856
>>>>>>

S
o I guess its not unusual for liquid to leak.

KB


--

"K. B." > wrote in message
...
> Thank you, I did write using the link you provided and will post the
reply!
>
> KB
> Saint Charles County, Missouri
>
>
> "Ed Marks" > wrote in message
> ...
> > I have no idea - but your observation made me go back and look at the
> titret
> > information sheet. I really hadn't paid attention to whether there was
> > anything in the valve assemble that you put onto the ampule, and found
out
> > there is. Supposedly it has approximately .05 ml of phosphoric acid -
> which
> > I can see in the harder plastic tube ahead of the valve. I assume this
> > needs to get into the ampule when you press on the valve, to acidify the
> > wine sample that goes into the ampule and release the SO2 to react with
> the
> > reagents in the ampule. If, for some reason, the phosphoric acid is
going
> > out of the valve assembly rather than into the ampule, you are probably
> not
> > getting an accurate test result - unless Chemetrics assumes a small
amount
> > will come out and it doesn't matter. That's my interpretation at
least -
> > why don't you send an e-mail to Chemetrics
> > (http://www.chemetrics.com/contact.html and select "Technical
Questions")
> > and see what they say. If you do that, please share what you hear from
> > them.
> >
> > Ed
> >
> >
> >
> > "K. B." > wrote in message
> > ...
> > >
> > >
> > > "Ed Marks" > wrote in message
> > > ...
> > > > Nothing should come out of the tip into the wine sample. Did you
> slide
> > > the
> > > > rubber tube with the valve all the way onto the ampule (to the white
> > line)
> > > > before snapping the end of the ampule? Yes there's a starch
solution
> in
> > > the
> > > > ampule, but it shouldn't come out due to the vacuum in the ampule.
> > > >
> > > > Ed
> > > >
> > >
> > >
> > > I slid the tube all the way over the ampule and then snapped. When I
> > placed
> > > the tube in the sample, before squeezing the tube, you could see the
> > mixing
> > > of the contents of the tube with the sample. However, the ampule
turned
> > > almost black, and stayed that way until about the 10 marking on the
> ampule
> > > (it then started to fade). At 15 it was almost back to the original
> color
> > of
> > > the sample. Something did definitely come out of the end into the
> sample.
> > > Is the test still valid?
> > >
> > > KB
> > >
> > >
> >
> >
>
>

I wrote chemetrics as suggested and asked the following questions:
1) Is it normal for liquid to appear at the titret tip after snapping
the score?
2) Is it normal for liquid from the titret to enter the wine sample?
3) Will the results be accurate (in this case 15 mg/l was indicated).

Here is Chemetrics Response:

<<It is not unusual for a drop or two of the valve assembly's content to be
lost
when the valve assembly is attached to the ampoule, or when the ampoule is
snapped at the score mark. This is not a problem if only a drop of the
assembly's contents is dispensed into the sample prior to its introduction
into
the test ampoule. However, the majority of the assembly's content should
enter
the test ampoule, so if all or most of the assembly's content enters the
sample
prior to beginning testing or is otherwise lost ,this is a problem.

As long as the user sees the blue color in the test ampoule, all is well.

I hope this helps. Please let me know if you have additional questions.

Regards,


Technical Services
Chemetrics, Inc.
ph: 540-788-9026
fax: 540-788-4856
>>>>>>

S
o I guess its not unusual for liquid to leak.

KB


--

"K. B." > wrote in message
...
> Thank you, I did write using the link you provided and will post the
reply!
>
> KB
> Saint Charles County, Missouri
>
>
> "Ed Marks" > wrote in message
> ...
> > I have no idea - but your observation made me go back and look at the
> titret
> > information sheet. I really hadn't paid attention to whether there was
> > anything in the valve assemble that you put onto the ampule, and found
out
> > there is. Supposedly it has approximately .05 ml of phosphoric acid -
> which
> > I can see in the harder plastic tube ahead of the valve. I assume this
> > needs to get into the ampule when you press on the valve, to acidify the
> > wine sample that goes into the ampule and release the SO2 to react with
> the
> > reagents in the ampule. If, for some reason, the phosphoric acid is
going
> > out of the valve assembly rather than into the ampule, you are probably
> not
> > getting an accurate test result - unless Chemetrics assumes a small
amount
> > will come out and it doesn't matter. That's my interpretation at
least -
> > why don't you send an e-mail to Chemetrics
> > (http://www.chemetrics.com/contact.html and select "Technical
Questions")
> > and see what they say. If you do that, please share what you hear from
> > them.
> >
> > Ed
> >
> >
> >
> > "K. B." > wrote in message
> > ...
> > >
> > >
> > > "Ed Marks" > wrote in message
> > > ...
> > > > Nothing should come out of the tip into the wine sample. Did you
> slide
> > > the
> > > > rubber tube with the valve all the way onto the ampule (to the white
> > line)
> > > > before snapping the end of the ampule? Yes there's a starch
solution
> in
> > > the
> > > > ampule, but it shouldn't come out due to the vacuum in the ampule.
> > > >
> > > > Ed
> > > >
> > >
> > >
> > > I slid the tube all the way over the ampule and then snapped. When I
> > placed
> > > the tube in the sample, before squeezing the tube, you could see the
> > mixing
> > > of the contents of the tube with the sample. However, the ampule
turned
> > > almost black, and stayed that way until about the 10 marking on the
> ampule
> > > (it then started to fade). At 15 it was almost back to the original
> color
> > of
> > > the sample. Something did definitely come out of the end into the
> sample.
> > > Is the test still valid?
> > >
> > > KB
> > >
> > >
> >
> >
>
>

I wrote chemetrics as suggested and asked the following questions:
1) Is it normal for liquid to appear at the titret tip after snapping
the score?
2) Is it normal for liquid from the titret to enter the wine sample?
3) Will the results be accurate (in this case 15 mg/l was indicated).

Here is Chemetrics Response:

<<It is not unusual for a drop or two of the valve assembly's content to be
lost
when the valve assembly is attached to the ampoule, or when the ampoule is
snapped at the score mark. This is not a problem if only a drop of the
assembly's contents is dispensed into the sample prior to its introduction
into
the test ampoule. However, the majority of the assembly's content should
enter
the test ampoule, so if all or most of the assembly's content enters the
sample
prior to beginning testing or is otherwise lost ,this is a problem.

As long as the user sees the blue color in the test ampoule, all is well.

I hope this helps. Please let me know if you have additional questions.

Regards,


Technical Services
Chemetrics, Inc.
ph: 540-788-9026
fax: 540-788-4856
>>>>>>

S
o I guess its not unusual for liquid to leak.

KB


--

"K. B." > wrote in message
...
> Thank you, I did write using the link you provided and will post the
reply!
>
> KB
> Saint Charles County, Missouri
>
>
> "Ed Marks" > wrote in message
> ...
> > I have no idea - but your observation made me go back and look at the
> titret
> > information sheet. I really hadn't paid attention to whether there was
> > anything in the valve assemble that you put onto the ampule, and found
out
> > there is. Supposedly it has approximately .05 ml of phosphoric acid -
> which
> > I can see in the harder plastic tube ahead of the valve. I assume this
> > needs to get into the ampule when you press on the valve, to acidify the
> > wine sample that goes into the ampule and release the SO2 to react with
> the
> > reagents in the ampule. If, for some reason, the phosphoric acid is
going
> > out of the valve assembly rather than into the ampule, you are probably
> not
> > getting an accurate test result - unless Chemetrics assumes a small
amount
> > will come out and it doesn't matter. That's my interpretation at
least -
> > why don't you send an e-mail to Chemetrics
> > (http://www.chemetrics.com/contact.html and select "Technical
Questions")
> > and see what they say. If you do that, please share what you hear from
> > them.
> >
> > Ed
> >
> >
> >
> > "K. B." > wrote in message
> > ...
> > >
> > >
> > > "Ed Marks" > wrote in message
> > > ...
> > > > Nothing should come out of the tip into the wine sample. Did you
> slide
> > > the
> > > > rubber tube with the valve all the way onto the ampule (to the white
> > line)
> > > > before snapping the end of the ampule? Yes there's a starch
solution
> in
> > > the
> > > > ampule, but it shouldn't come out due to the vacuum in the ampule.
> > > >
> > > > Ed
> > > >
> > >
> > >
> > > I slid the tube all the way over the ampule and then snapped. When I
> > placed
> > > the tube in the sample, before squeezing the tube, you could see the
> > mixing
> > > of the contents of the tube with the sample. However, the ampule
turned
> > > almost black, and stayed that way until about the 10 marking on the
> ampule
> > > (it then started to fade). At 15 it was almost back to the original
> color
> > of
> > > the sample. Something did definitely come out of the end into the
> sample.
> > > Is the test still valid?
> > >
> > > KB
> > >
> > >
> >
> >
>
>

Great! Thanks for sharing Chemetrics response.

Ed

"K. B." > wrote in message
.. .
> I wrote chemetrics as suggested and asked the following questions:
> 1) Is it normal for liquid to appear at the titret tip after snapping
> the score?
> 2) Is it normal for liquid from the titret to enter the wine sample?
> 3) Will the results be accurate (in this case 15 mg/l was indicated).
>
> Here is Chemetrics Response:
>
> <<It is not unusual for a drop or two of the valve assembly's content to
be
> lost
> when the valve assembly is attached to the ampoule, or when the ampoule is
> snapped at the score mark. This is not a problem if only a drop of the
> assembly's contents is dispensed into the sample prior to its introduction
> into
> the test ampoule. However, the majority of the assembly's content should
> enter
> the test ampoule, so if all or most of the assembly's content enters the
> sample
> prior to beginning testing or is otherwise lost ,this is a problem.
>
> As long as the user sees the blue color in the test ampoule, all is well.
>
> I hope this helps. Please let me know if you have additional questions.
>
> Regards,
>
>
> Technical Services
> Chemetrics, Inc.
> ph: 540-788-9026
> fax: 540-788-4856
> >>>>>>
>
> S
> o I guess its not unusual for liquid to leak.
>
> KB
>
>

Great! Thanks for sharing Chemetrics response.

Ed

"K. B." > wrote in message
.. .
> I wrote chemetrics as suggested and asked the following questions:
> 1) Is it normal for liquid to appear at the titret tip after snapping
> the score?
> 2) Is it normal for liquid from the titret to enter the wine sample?
> 3) Will the results be accurate (in this case 15 mg/l was indicated).
>
> Here is Chemetrics Response:
>
> <<It is not unusual for a drop or two of the valve assembly's content to
be
> lost
> when the valve assembly is attached to the ampoule, or when the ampoule is
> snapped at the score mark. This is not a problem if only a drop of the
> assembly's contents is dispensed into the sample prior to its introduction
> into
> the test ampoule. However, the majority of the assembly's content should
> enter
> the test ampoule, so if all or most of the assembly's content enters the
> sample
> prior to beginning testing or is otherwise lost ,this is a problem.
>
> As long as the user sees the blue color in the test ampoule, all is well.
>
> I hope this helps. Please let me know if you have additional questions.
>
> Regards,
>
>
> Technical Services
> Chemetrics, Inc.
> ph: 540-788-9026
> fax: 540-788-4856
> >>>>>>
>
> S
> o I guess its not unusual for liquid to leak.
>
> KB
>
>