Antek Sulfur In Naphtha

Question 1

1. Purpose

Answer 1

Similar to sulfur in LPG

Question 2

2. Initial operating conditions

Answer 2

• check compressed gases
• verify waste hose is in jar and not obstructed, check that it is not full
• verify septum is not horizontal and not vertical in pyro tube
• check back rinse/purge reservoir is filled with iso-octane. It is used for purging and cleaning the needle. Front reservoir not used
• system should go into shutdown method if not used for a couple hours
• go to main screen select method and Los proper method
• on Antek 1 be sure you are in data folder when selecting method (method for finished gasoline and GDU samples is 0-75ppm. For 77stripper bottoms, plt2 stripper bottoms , plant 3 rx chg, or other low samples it is 0-1.
• Antek 1 operates in 24 hour file period starting at 7am. If within 24 hour period, use old file, if not create new file

Question 3

3. Creating sample sequence

Answer 3

• enter total number of blanks,standards, and samples in unknowns box and number of injections per vial is always 4
• next use name samples option
• be sure user defined number is checked and it is 1.0000
• click name field to identify samples. You may also enter density of samples in Wt/Div column. If you do this, you do not divide final result again. If dilution I used, enter it in multiplier columns if diluted 50mLs sample into 50mLs Iso, multiplier would be 2.
• be sure to edit tray number and tray position if necessary
• click next and verify correct method file is chosen and method name does not say shutdown. If you run analysis in shutdown method, severe instrument damage can occur.

Question 4

4. Sample preparation

Answer 4

•stds and samples should be shaken to mix contents. Invert bottle two or three times. Use iso-octane dispenser to fill amber screw-top vials with iso-octane for blanks. Vial should be filled close to neck of vile. Use roll pipettor with glass disposable pipettes to fill standard and sample vials using standards and quart samples of top,middle,and bottom for gasoline. GDU samples may be obtained from quart sample bottles
•attach screw top to vial. Be careful not to tighten cap too tightly as this could prevent needle from penetrating septum. Cap should be freely turning but should not see indentation of septum
•label vile to prevent analyzing wrong sample or standard
GDU stabilizer bottoms may or may not need diluted . Check results backlog to see what it has been running. Splitter side draw always needs diluted, because it is so light.
•typically samples run on 0-1ppm method don’t need diluted
•place properly labeled vials in front left tray
•sulfur standards are stored in walk-in cooler. Be sure to check out when needed
•iso octane should be analyzed at beginning and end of sequence
•if std doesn’t hit, you can stop run, adjust voltage, run std again and continue run if it is good

Question 5

5. Data analysis and calculation

Answer 5

Best way to view plots is to select view button along bottom and select sample chart. This cannot be accomplished while sequence is running. This will place all injection plots in screen and allow you to verify none of them flat topped. If inject plot looks out of line compared to others, you could choose not to use it
•verify total sulfur counts do not exceed those of highest calibration standards
•if %RSD is not

Question 6

6. Shutdown

Answer 6

Similar to Antek in LPG shutdown

Question 7

7. Syringe replacement

Answer 7

• if you notice bubbles in syringe or notice high RSD values combined with low QC results, may indicate worn syringe.
• Antek sulfur instrument uses a 100 microliter syringe. Stored in stockroom, be sure to dibble check him are replacing the correct syringe
• you may either use LEAP Pal to change syringe or leave it in position to change it. LEAP Pal moves syringe to the right to make it easier to change.
• once syringe is jn position off to right of jnstrumsnt, grasp small black knob to raise door on assembly. Need to loosen red thumb screw. Undo black clip which holds body of syringe in place. Pull top of syringe toward you and lift up and pull in syringe to remove it from assembly
• take new syringe and draw isooctane into syringe several times to prime it
• place syringe tip into bottom port first. Push body of syringe into place being sure thicker part of top fits in groove and plunger goes into place
• slide bottom mechanism up to verify syringe goes through injection port
• move black know which holds syringe in place to horizontal position and tighten red thumb acre which holds plunger