##### QADATA Summary -- July 2002

The Inorganic Blind Sample Project (IBSP) reviews 97 inorganic
analytical lines at the National Water Quality Laboratory (NWQL) and 68
inorganic analytical lines at the Ocala Water Quality and Research
Laboratory (OWQRL) using double-blind, quality-assurance samples. This
QADATA Summary is a report that includes a short summary of only those
analytical lines for which the quality-assurance charts indicate or have
indicated a bias and/or lack of precision. Quality-assurance charts for
all other analytical lines reviewed demonstrate acceptable bias and
precision. The data reviewed is for the time period 12/20/01 through
06/20/02. The quality-assurance charts contain data from samples that
have been subject to the same laboratory handling procedures as the
samples that are submitted by the USGS district offices, and the data
have the same level of quality control-review as the data released to
the districts. Thus, any factors that affect the district's data should
also affect the data shown in the IBSP quality-assurance charts as well.
IBSP outliers are reanalyzed but are not updated unless it is determined
that the sample had deteriorated or had been contaminated before
submittal, or an IBSP sample mix-up occurred.

Lab personnel and customers can make their own QADATA retrieval to
parallel their project's sampling period by using the QADATA application
online at <http://bqs.usgs.gov/bsp/mainpage.html>. Charts containing all
data received thus far for water year 2002 may be accessed at
<http://bqs.usgs.gov/bsp/WY02charts.htm>.

Most of the control charts for zinc determinations indicate high bias
and poor precision (<http://bqs.usgs.gov/bsp/WY02charts.htm>). This is
indicative of possible contamination and may be originating from the
IBSP. The problem is not reflected on the quality-assurance charts for
the ICPs used at the NWQL because the concentration of zinc in most of
the quality-assurance samples submitted to the NWQL is either less than
the ICPs' Long-Term Method Detection Limit (LTMDL) or between the LTMDL
and the Laboratory Reporting Level (LRL). Since results less than the
LTMDL and results between the LTMDL and LRL are currently compared to
wider limits than results above the LRL, this tends to group the NWQL's
zinc data from ICP within\
+/- 2 f-pseudosigma even when the results indicate high variability. The
source of the zinc contamination will be researched further, and how to
more meaningfully plot results less than the LTMDL and results between
the LTMDL and LRL will be addressed in the future.

*Tedmund M. Struzeski*

<struzesk@usgs.gov>

Table 1

NWQL PERFORMANCE ON IBSP SAMPLES

######### 

######### **Note: Click the blue, underlined text in the left column to access the control chart for the associated parameter.**

#########  

+----------+------------------+--------------------+------------------+
| **       | **Problem**      | **NWQL**           | **Corrective**   |
| Nutrient |                  |                    |                  |
| Determin |                  | **Lab Comment**    | **Action**       |
| ations** |                  |                    |                  |
+==========+==================+====================+==================+
| [*       | Negative bias    | The Nutrients Unit | Calibration      |
| *Nitrate | since January    | had observed this  | standards will   |
| +Nitrite | 2002. The        | bias several weeks | be made more     |
| Fil      | magnitude of the | ago, and took      | frequently and   |
| tered**] | bias has been    | steps to correct   | tested with new  |
| (http:// | increasing       | the problem. New   | commercially     |
| bqs.usgs | steadily over    | standards and a    | prepared         |
| .gov/bsp | the course of    | new cadmium column | certified QC     |
| /QADATA_ | five months;     | (using             | samples.         |
| all/JUL0 | however, the     | re-activated Cd)   |                  |
| 2NWQL006 | last two data    | were made and the  |                  |
| 31F.gif) | points           | values for the QC  |                  |
|          | demonstrate      | samples prepared   |                  |
| **Aci    | marked           | at the NWQL (made  |                  |
| dified** | improvement.     | from the same      |                  |
|          | Other methods at | source material as |                  |
| **labc   | the NWQL and the | the IBSP samples)  |                  |
| ode=1990 | OWQRL reporting  | no longer          |                  |
| parmcod  | filtered         | displayed the bias |                  |
| e=631F** | nitrate- plus    | evident on the BQS |                  |
|          | nitrite-nitrogen | QC charts.         |                  |
|          | do not indicate  |                    |                  |
|          | a bias.          |                    |                  |
+----------+------------------+--------------------+------------------+
| [Ph      | An abrupt high   | The Nutrients Unit | The Nutrients    |
| osphorus | bias starting in | has been           | Unit will        |
| F        | April, although  | investigating this | continue the     |
| iltered] | somewhat         | apparent bias by   | investigation of |
| (http:// | improved, is     | comparing the      | the apparent     |
| bqs.usgs | still prevalent. | results of         | high bias with   |
| .gov/bsp | Two other        | identical samples  | the assistance   |
| /QADATA_ | analytical lines | run on several     | of the Methods   |
| all/JUL0 | at the NWQL      | different          | Research and     |
| 2NWQL006 | testing for      | instruments. To    | Development      |
| 66G.gif) | phosphorus and   | date the only      | Program.         |
|          | the four lines   | sample that has    |                  |
| **Color  | testing for      | had values that    |                  |
| imetric, | phosphorus at    | consistently       |                  |
| LL       | the OWQRL do not | differ from the    |                  |
| labc     | demonstrate this | value of the MPV   |                  |
| ode=2331 | problem.         | is N73 run on the  |                  |
| parmcod  |                  | Low-Level Total    |                  |
| e=666G** |                  | Phosphorus         |                  |
|          |                  | instrument. New    |                  |
|          |                  | calibration        |                  |
|          |                  | standards have     |                  |
|          |                  | been made several  |                  |
|          |                  | times since April. |                  |
|          |                  | SRS N71 and two    |                  |
|          |                  | certified          |                  |
|          |                  | reference          |                  |
|          |                  | standards run on   |                  |
|          |                  | the LL Total       |                  |
|          |                  | Phosphorus         |                  |
|          |                  | instrument have    |                  |
|          |                  | exhibited no bias. |                  |
+----------+------------------+--------------------+------------------+
| [Ph      | Abrupt high bias | Calibration        | See above.       |
| osphorus | starting in      | standards and      |                  |
| Whole    | April. High bias | reference samples  |                  |
| Water    | decreased        | are prepared from  |                  |
| Reco     | throughout May,  | the same stocks    |                  |
| verable] | however, bias is | for this parameter |                  |
| (http:// | once again       | as those that are  |                  |
| bqs.usgs | increasing. Two  | used for Filtered, |                  |
| .gov/bsp | other analytical | Total Phosphorus   |                  |
| /QADATA_ | lines at the     | (LC 2331, PC       |                  |
| all/JUL0 | NWQL testing for | 666G).             |                  |
| 2NWQL006 | phosphorus and   |                    |                  |
| 65G.gif) | the four lines   |                    |                  |
|          | testing for      |                    |                  |
| **Color  | phosphorus at    |                    |                  |
| imetric, | the OWQRL do not |                    |                  |
| LL       | exhibit this     |                    |                  |
| labc     | problem.         |                    |                  |
| ode=2333 |                  |                    |                  |
| parmcod  |                  |                    |                  |
| e=665G** |                  |                    |                  |
+----------+------------------+--------------------+------------------+
| [Ph      | A high bias      | The small high     | The NWQL will    |
| osphorus | appears in April | bias for this      | continue to      |
| F        | but is less      | parameter is no    | monitor the      |
| iltered] | apparent in May. | longer evident.    | results for IBSP |
| (http:// | Two other        | The same           | samples for any  |
| bqs.usgs | analytical lines | calibration        | deviations of    |
| .gov/bsp | at the NWQL      | standards and      | the values for   |
| /QADATA_ | testing for      | certified QC       | total            |
| all/JUL0 | phosphorus and   | samples are used   | phosphorus.      |
| 2NWQL006 | the four lines   | on all three       |                  |
| 66D.gif) | testing for      | regular- level     |                  |
|          | phosphorus at    | Total Phosphorus   |                  |
| **Colo   | the OWQRL do not | analyses. New      |                  |
| rimetric | demonstrate this | calibration        |                  |
| labc     | pattern.         | standards were     |                  |
| ode=1983 |                  | prepared, tested,  |                  |
| parmcod  | Line should be   | and used during    |                  |
| e=666D** | closely          | the time period of |                  |
|          | monitored until  | the high bias. All |                  |
|          | next QADATA      | QC sample values   |                  |
|          | summary          | were well within   |                  |
|          | published.       | acceptable limits  |                  |
|          |                  | for all three      |                  |
|          |                  | parameters during  |                  |
|          |                  | the time period of |                  |
|          |                  | this report        |                  |
|          |                  | although there was |                  |
|          |                  | a small shift      |                  |
|          |                  | upward during the  |                  |
|          |                  | time of the small  |                  |
|          |                  | high bias.         |                  |
+----------+------------------+--------------------+------------------+

Table 1 -- Cont'd

NWQL PERFORMANCE ON IBSP SAMPLES

Note: Click the blue, underlined text in the left column to access the
control chart for the associated parameter.

+----------+------------------+--------------------+------------------+
| **Trace  | **Problem**      | **NWQL**           | **Corrective**   |
| Metal    |                  |                    |                  |
| Determin |                  | **Lab Comment**    | **Action**       |
| ations** |                  |                    |                  |
+==========+==================+====================+==================+
| [        | Historical low   | We are continuing  | We are           |
| **Barium | bias appears to  | to monitor.        | continuing to    |
| Whole    | have improved in |                    | monitor.         |
| Water    | the last month.  |                    |                  |
| Recove   |                  |                    |                  |
| rable**] | Line should be   |                    |                  |
| (http:// | closely          |                    |                  |
| bqs.usgs | monitored until  |                    |                  |
| .gov/bsp | next QADATA      |                    |                  |
| /QADATA_ | summary          |                    |                  |
| all/JUL0 | published.       |                    |                  |
| 2NWQL010 |                  |                    |                  |
| 07C.gif) |                  |                    |                  |
|          |                  |                    |                  |
| **ICP**  |                  |                    |                  |
|          |                  |                    |                  |
| **labc   |                  |                    |                  |
| ode=2352 |                  |                    |                  |
| parmcode |                  |                    |                  |
| =1007C** |                  |                    |                  |
+----------+------------------+--------------------+------------------+
| [**      | A high bias and  | April's bench QC   | All instruments  |
| Chromium | increased        | indicated that     | have had factory |
| Fil      | variability      | chromium was       | periodic         |
| tered**] | (with two points | running above the  | maintenance      |
| (http:// | greater than +2  | MPV for most SRS.  | performed and    |
| bqs.usgs | SD) start in     | A new standard was | new chromium     |
| .gov/bsp | April. Other     | prepared but daily | hollow-cathode   |
| /QADATA_ | methods          | QC results soon    | lamps have been  |
| all/JUL0 | reporting this   | returned to        | installed. The   |
| 2NWQL010 | parameter do not | previously biased  | SOP is being     |
| 30I.gif) | indicate a bias. | values. Another    | updated to       |
|          |                  | standard set was   | reflect changes  |
| **GFAA   |                  | prepared but this  | to the           |
| labc     |                  | time the stock     | concentration    |
| ode=1936 |                  | standard used was  | and type of      |
| parmcode |                  | made from          | primary          |
| =1030I** |                  | elemental chromium | commercial stock |
|          |                  | not Ammonium       | used and matrix  |
|          |                  | Dichromate.        | modifier. The    |
|          |                  | Testing indicated  | metals unit is   |
|          |                  | that values were   | converting all   |
|          |                  | within limits, but | old 1000 ug/mL   |
|          |                  | again still        | stocks used for  |
|          |                  | slightly biased. A | GFAA to 10,000   |
|          |                  | final set was      | ug/mL stocks to  |
|          |                  | prepared and then  | make inventory   |
|          |                  | verified by ICP.   | easier and more  |
|          |                  | Currently, values  | uniform with ICP |
|          |                  | are running very   | and ICP-MS       |
|          |                  | close to MPV for   | standards.       |
|          |                  | the current SRS    |                  |
|          |                  | used. Performance  |                  |
|          |                  | improved with a    |                  |
|          |                  | change from a      |                  |
|          |                  | mixed modifier to  |                  |
|          |                  | a single magnesium |                  |
|          |                  | nitrate solution.  |                  |
|          |                  |                    |                  |
|          |                  | Results of ICAP    |                  |
|          |                  | verification:      |                  |
|          |                  |                    |                  |
|          |                  |                    |                  |
|          |                  | --------------- -- |                  |
|          |                  | ----- ------------ |                  |
|          |                  |   Ideal            |                  |
|          |                  |    ICP     Percent |                  |
|          |                  |   concentration    |                  |
|          |                  | value   difference |                  |
|          |                  |                    |                  |
|          |                  |   25000 ug/L       |                  |
|          |                  |      24820   -.725 |                  |
|          |                  |                    |                  |
|          |                  |           ug/L     |                  |
|          |                  |                    |                  |
|          |                  |   250 ug/L         |                  |
|          |                  |      246.1   -1.58 |                  |
|          |                  |                    |                  |
|          |                  |           ug/L     |                  |
|          |                  |                    |                  |
|          |                  | --------------- -- |                  |
|          |                  | ----- ------------ |                  |
+----------+------------------+--------------------+------------------+
| [**      | This analytical  | We have been       | New standards    |
| Antimony | line is          | looking at QC      | have been        |
| Fil      | exhibiting a     | charts concerning  | prepared and we  |
| tered**] | high bias. The   | the high bias      | will continue to |
| (http:// | bias started     | noted for          | monitor closely. |
| bqs.usgs | near the         | dissolved          |                  |
| .gov/bsp | beginning of     | antimony - ICPMS.  |                  |
| /QADATA_ | March.           | It appears to have |                  |
| all/JUL0 |                  | been a result of   |                  |
| 2NWQL010 |                  | the standards that |                  |
| 95G.gif) |                  | have been in use   |                  |
|          |                  | since about that   |                  |
| **ICP-MS |                  | time.              |                  |
| labc     |                  |                    |                  |
| ode=1785 |                  |                    |                  |
| parmcode |                  |                    |                  |
| =1095G** |                  |                    |                  |
+----------+------------------+--------------------+------------------+

###### 

Table 1 -- Cont'd

NWQL PERFORMANCE ON IBSP SAMPLES

Note: Click the blue, underlined text in the left column to access the
control chart for the associated parameter.

+----------+------------------+--------------------+------------------+
| **Trace  | **Problem**      | **NWQL**           | **Corrective**   |
| Metal    |                  |                    |                  |
| Determin |                  | **Lab Comment**    | **Action**       |
| ations** |                  |                    |                  |
+==========+==================+====================+==================+
| [**Lead  | Actions taken by |                    |                  |
| Whole    | the NWQL appear  |                    |                  |
| Water    | to have improved |                    |                  |
| Recove   | the precision    |                    |                  |
| rable**] | and positive     |                    |                  |
| (http:// | bias problems    |                    |                  |
| bqs.usgs | previously       |                    |                  |
| .gov/bsp | demonstrated by  |                    |                  |
| /QADATA_ | this analytical  |                    |                  |
| all/JUL0 | line.            |                    |                  |
| 2NWQL010 |                  |                    |                  |
| 51F.gif) | No corrective    |                    |                  |
|          | action           |                    |                  |
| **GFAA   | necessary.       |                    |                  |
| labc     |                  |                    |                  |
| ode=1561 |                  |                    |                  |
| parmcode |                  |                    |                  |
| =1051F** |                  |                    |                  |
+----------+------------------+--------------------+------------------+

+----------+------------------+--------------------+------------------+
| **Major  | **Problem**      | **NWQL**           | **Corrective**   |
| Ion      |                  |                    |                  |
| Determin |                  | **Lab Comment**    | **Action**       |
| ations** |                  |                    |                  |
+==========+==================+====================+==================+
| [**P     | Analytical line  | The negative bias  | New calibration  |
| otassium | demonstrates an  | started when new   | standards have   |
| Fil      | overall negative | calibration        | been made and    |
| tered**] | bias.            | standards were put | the line will be |
| (http:// |                  | online in November | monitored for    |
| bqs.usgs |                  | 2001. New          | any bias.        |
| .gov/bsp |                  | standards are      |                  |
| /QADATA_ |                  | always compared to |                  |
| all/JUL0 |                  | old standards and  |                  |
| 2NWQL009 |                  | must fall within a |                  |
| 35B.gif) |                  | +/- 2% window.     |                  |
|          |                  | Reviewing online   |                  |
| **labc   |                  | QC and blanks for  |                  |
| ode=0054 |                  | the time period in |                  |
| p        |                  | question showed no |                  |
| armcode= |                  | deviation from     |                  |
| 00935B** |                  | acceptable limits. |                  |
+----------+------------------+--------------------+------------------+

######  

###### Table 2

OWQRL PERFORMANCE ON IBSP SAMPLES

**Note: Click the blue, underlined text in the left column to access the
control chart for the associated parameter.**

+----------+------------------+--------------------+------------------+
| **       | **Problem**      | **OWQRL Lab**      | **Corrective**   |
| Nutrient |                  |                    |                  |
| Determin |                  | **Comment**        | **Action**       |
| ations** |                  |                    |                  |
+==========+==================+====================+==================+
| **[A     | Although the     | The plot has       | We will continue |
| mmonia-N | precision        | looked better      | to monitor this  |
| Whole    | appears to be    | since the          | line.            |
| Water    | improving over   | beginning of May   |                  |
| Recov    | time, there are  | and is paralleling |                  |
| erable]( | two out of 14    | what we see in our |                  |
| http://b | points (14%)     | internal control   |                  |
| qs.usgs. | outside of 2 SD  | charts.            |                  |
| gov/bsp/ | since the        |                    |                  |
| QADATA_a | beginning of     |                    |                  |
| ll/JUL02 | March.           |                    |                  |
| OCALA006 |                  |                    |                  |
| 10F.gif) | Line should be   |                    |                  |
| labc     | closely          |                    |                  |
| ode=3071 | monitored until  |                    |                  |
| parmcod  | next QADATA      |                    |                  |
| e=610F** | summary          |                    |                  |
|          | published.       |                    |                  |
+----------+------------------+--------------------+------------------+
| **[Ammon | This analytical  | The bias and       | We are           |
| ia+Org-N | line still       | variability here   | continuing to    |
| Whole    | exhibits a high  | has improved since | investigate      |
| Water    | bias. Other      | March. Part of the | this. The        |
| Recov    | methods at the   | problem is that    | rounding for TKN |
| erable]( | OWQRL and the    | the data from our  | is being changed |
| http://b | NWQL reporting   | new LIMS in the    | to 2 significant |
| qs.usgs. | ammonia plus     | range of the       | figures for      |
| gov/bsp/ | organic nitrogen | submitted samples  | samples less     |
| QADATA_a | do not indicate  | is being rounded   | than 1 ppm.      |
| ll/JUL02 | a bias.          | to 1 significant   |                  |
| OCALA006 |                  | figure. The same   |                  |
| 25D.gif) |                  | bias is not        |                  |
| labc     |                  | evident for        |                  |
| ode=1986 |                  | dissolved TKN      |                  |
| parmcod  |                  | which is run at    |                  |
| e=625D** |                  | the same time on   |                  |
|          |                  | the same blind     |                  |
|          |                  | samples.           |                  |
+----------+------------------+--------------------+------------------+
| [**Pho   | Overall line     | This bias is only  | We are           |
| sporus-P | still indicates  | shown in the low   | investigating    |
| Whole    | a slight low     | level sample, N73. | the use of the   |
| Water    | bias with most   | N74, the high      | EPA digestion    |
| Recover  | recent data      | level sample, is   | that we use on   |
| able**]( | around -3 SD.    | not showing this   | low level        |
| http://b | Six out of 36    | bias.              | phosphorus with  |
| qs.usgs. | points (17%) are |                    | our high level   |
| gov/bsp/ | outside of -2    |                    | samples. The     |
| QADATA_a | SD.              |                    | current          |
| ll/JUL02 |                  |                    | digestion may    |
| OCALA006 |                  |                    | bias the results |
| 65D.gif) |                  |                    | at the lower     |
|          |                  |                    | levels of the    |
| **labc   |                  |                    | calibration due  |
| ode=1984 |                  |                    | to incomplete    |
| parmcod  |                  |                    | digestion.       |
| e=665D** |                  |                    |                  |
+----------+------------------+--------------------+------------------+
| [**Pho   | Overall slight   | The samples in the | We will continue |
| sporus-P | high bias still  | last month do not  | to monitor this  |
| Whole    | evident, but     | show this bias.    | line.            |
| Water    | data seem to be  |                    |                  |
| Rec      | closer to the    |                    |                  |
| overable | MPV for the last |                    |                  |
| Low-l    | three months.    |                    |                  |
| evel**]( |                  |                    |                  |
| http://b | Line should be   |                    |                  |
| qs.usgs. | closely          |                    |                  |
| gov/bsp/ | monitored until  |                    |                  |
| QADATA_a | next QADATA      |                    |                  |
| ll/JUL02 | summary          |                    |                  |
| OCALA006 | published.       |                    |                  |
| 65F.gif) |                  |                    |                  |
|          |                  |                    |                  |
| **labc   |                  |                    |                  |
| ode=1982 |                  |                    |                  |
| parmcod  |                  |                    |                  |
| e=665F** |                  |                    |                  |
+----------+------------------+--------------------+------------------+
| [**O     | A low bias       | There have not     | We will continue |
| rthophos | appears to be    | been that many     | to monitor this  |
| phorus-P | developing.      | blind samples      | line.            |
| Whole    |                  | submitted recently |                  |
| Water    | Line should be   | on this line (only |                  |
| Rec      | closely          | 2 since March).    |                  |
| overable | monitored until  | Other o-PO4 lines  |                  |
| Low-l    | next QADATA      | run at the same    |                  |
| evel**]( | summary          | time are not       |                  |
| http://b | published.       | showing this bias, |                  |
| qs.usgs. |                  | nor do our         |                  |
| gov/bsp/ |                  | internal control   |                  |
| QADATA_a |                  | charts.            |                  |
| ll/JUL02 |                  |                    |                  |
| OCALA705 |                  |                    |                  |
| 07D.gif) |                  |                    |                  |
|          |                  |                    |                  |
| **labc   |                  |                    |                  |
| ode=3233 |                  |                    |                  |
| p        |                  |                    |                  |
| armcode= |                  |                    |                  |
| 70507D** |                  |                    |                  |
+----------+------------------+--------------------+------------------+